1) The document discusses the development of atomic physics models from Dalton's billiard ball model to Thomson's plum pudding model to Rutherford's nuclear model.
2) It then explains Planck's solution to the ultraviolet catastrophe by introducing the idea of quantized energy packets called quanta.
3) Bohr used Planck's idea of quantized energy to explain atomic spectra, proposing that electrons in atoms can only occupy discrete energy levels corresponding to distinct orbital radii. When electrons jump between these levels, photons of specific frequencies are emitted or absorbed.
- The document discusses Bohr's atomic model of hydrogen and its energy levels.
- Bohr proposed that electrons in hydrogen orbit the nucleus in discrete, quantized energy levels and orbits. Only certain orbits are allowed corresponding to specific energy levels.
- Transitions between energy levels result in the emission or absorption of electromagnetic radiation of specific frequencies and wavelengths.
- The energy levels of hydrogen are calculated based on Bohr's model and equations. The ground state has the lowest energy, with increasing energy levels corresponding to higher orbit numbers.
1) The document explains Johann Balmer's empirical formula for the emission spectrum of hydrogen and how it relates the energies of emitted photons to integer values.
2) It then discusses early quantum models like the "electron in a box" model which showed energy must be quantized.
3) Finally, it describes Erwin Schrödinger's wave equation theory of quantum mechanics which successfully explained the quantization of energy levels in hydrogen and allowed prediction of atomic emission spectra.
The document discusses wave-particle duality and electron diffraction. It begins by explaining wave-particle duality, stating that particles can behave as waves and vice versa. It then discusses the Davisson-Germer experiment, which demonstrated that electrons diffract like waves, confirming de Broglie's hypothesis. The document concludes by discussing electron microscopes, which use the wave properties of electrons to achieve higher resolutions than optical microscopes.
The document summarizes Rutherford's alpha scattering experiment and its implications. It showed that atoms have small, dense nuclei containing their mass, surrounded by empty space. This contradicted the plum pudding model of atoms as diffuse positive charges. Later, Bohr proposed his model of electrons orbiting in discrete energy levels, explaining atomic spectra. However, it did not fully resolve issues like why electrons don't collapse into the nucleus.
The document provides a history of the development of atomic structure models from ancient Greek philosophers' ideas of indivisible atoms to the modern quantum mechanical model. It describes key experiments and findings such as Thomson's discovery of electrons, Rutherford's gold foil experiment, and Bohr's model of electron orbits that led to modern atomic theory. The emission spectra of elements provided evidence that electrons exist in specific energy levels and orbitals within atoms.
The document discusses atomic structure and energy levels in atoms. It begins by focusing on the importance of the hydrogen atom in understanding atomic physics. The hydrogen atom can be solved exactly and its properties extended to other atoms. Its spectra allow for precision tests of theory. Later models like the Rutherford model and Bohr model improved upon the early "plum pudding" model. Bohr's model combined classical mechanics with Planck's idea of quantized energy levels to explain the discrete emission spectra of atoms. His four postulates introduced new ideas like stationary, quantized electron states that allowed atoms to retain energy.
This document discusses electronic transitions in hydrogen atoms that produce spectral lines. It explains that electrons in hydrogen atoms exist in discrete energy levels called principal quantum levels. Transitions between these levels emit or absorb photons of specific wavelengths. The Lyman, Balmer, and Paschen series are produced by transitions from higher levels to the n=1, n=2, and n=3 levels, respectively. Precise wavelengths are given for the lines in the Balmer series in the visible spectrum. Bohr's model of the hydrogen atom is able to accurately predict the wavelengths of these spectral lines.
How the Bohr Model of the Atom Accounts for Limitations with Classical Mechan...Thomas Oulton
This small essay concisely outlines how Classical mechanics was deemed unacceptable when describing the motions of electrons within an atom through the observations made by hydrogen spectra, and how this lead to a revolution in atomic theory. Included is a brief overview of how Bohr arrived at his model through applying quantum mechanics.
Written for; First year Undergraduate study,
Materials Science and Engineering,
The University of Sheffield
Graded at 78%
- The document discusses Bohr's atomic model of hydrogen and its energy levels.
- Bohr proposed that electrons in hydrogen orbit the nucleus in discrete, quantized energy levels and orbits. Only certain orbits are allowed corresponding to specific energy levels.
- Transitions between energy levels result in the emission or absorption of electromagnetic radiation of specific frequencies and wavelengths.
- The energy levels of hydrogen are calculated based on Bohr's model and equations. The ground state has the lowest energy, with increasing energy levels corresponding to higher orbit numbers.
1) The document explains Johann Balmer's empirical formula for the emission spectrum of hydrogen and how it relates the energies of emitted photons to integer values.
2) It then discusses early quantum models like the "electron in a box" model which showed energy must be quantized.
3) Finally, it describes Erwin Schrödinger's wave equation theory of quantum mechanics which successfully explained the quantization of energy levels in hydrogen and allowed prediction of atomic emission spectra.
The document discusses wave-particle duality and electron diffraction. It begins by explaining wave-particle duality, stating that particles can behave as waves and vice versa. It then discusses the Davisson-Germer experiment, which demonstrated that electrons diffract like waves, confirming de Broglie's hypothesis. The document concludes by discussing electron microscopes, which use the wave properties of electrons to achieve higher resolutions than optical microscopes.
The document summarizes Rutherford's alpha scattering experiment and its implications. It showed that atoms have small, dense nuclei containing their mass, surrounded by empty space. This contradicted the plum pudding model of atoms as diffuse positive charges. Later, Bohr proposed his model of electrons orbiting in discrete energy levels, explaining atomic spectra. However, it did not fully resolve issues like why electrons don't collapse into the nucleus.
The document provides a history of the development of atomic structure models from ancient Greek philosophers' ideas of indivisible atoms to the modern quantum mechanical model. It describes key experiments and findings such as Thomson's discovery of electrons, Rutherford's gold foil experiment, and Bohr's model of electron orbits that led to modern atomic theory. The emission spectra of elements provided evidence that electrons exist in specific energy levels and orbitals within atoms.
The document discusses atomic structure and energy levels in atoms. It begins by focusing on the importance of the hydrogen atom in understanding atomic physics. The hydrogen atom can be solved exactly and its properties extended to other atoms. Its spectra allow for precision tests of theory. Later models like the Rutherford model and Bohr model improved upon the early "plum pudding" model. Bohr's model combined classical mechanics with Planck's idea of quantized energy levels to explain the discrete emission spectra of atoms. His four postulates introduced new ideas like stationary, quantized electron states that allowed atoms to retain energy.
This document discusses electronic transitions in hydrogen atoms that produce spectral lines. It explains that electrons in hydrogen atoms exist in discrete energy levels called principal quantum levels. Transitions between these levels emit or absorb photons of specific wavelengths. The Lyman, Balmer, and Paschen series are produced by transitions from higher levels to the n=1, n=2, and n=3 levels, respectively. Precise wavelengths are given for the lines in the Balmer series in the visible spectrum. Bohr's model of the hydrogen atom is able to accurately predict the wavelengths of these spectral lines.
How the Bohr Model of the Atom Accounts for Limitations with Classical Mechan...Thomas Oulton
This small essay concisely outlines how Classical mechanics was deemed unacceptable when describing the motions of electrons within an atom through the observations made by hydrogen spectra, and how this lead to a revolution in atomic theory. Included is a brief overview of how Bohr arrived at his model through applying quantum mechanics.
Written for; First year Undergraduate study,
Materials Science and Engineering,
The University of Sheffield
Graded at 78%
This chapter discusses the optical properties of phonons in materials. It covers:
1) Optical and acoustic phonons - some interact directly with light, others cause light scattering.
2) Optical excitation of phonons - how phonons contribute to optical properties through the dielectric function.
3) Phonon polaritons - mixed phonon-photon excitations in crystals near resonance frequencies.
4) Light scattering - concepts of Brillouin, Raman, and Rayleigh scattering involving phonons.
5) Coherent Raman spectroscopy - an experimental technique that enhances weak Raman scattering signals.
A dimensionless quantity described as a fundamental physical constant characterizing the coupling strength of the electromagnetic interaction. Introduced by Sommerfeld in 1916 to describe the spacing of splitting of spectral lines in multi-electron atoms, it is formed from four physical constants: electric charge, speed of light in vacuo, Planck's constant and electric permittivity of free space.
The inverse fine structure constant (=137.035999...) represents the spin precession whirl no. of the electron. The electron exhibits a slight precession due to an imbalance of electrostatic and magnetostatic energy levels. Electric charge is a result of this spin precession and represents a loop closure failure (torsion defect) similar to topological charge.
Rest mass results from quantum wave interference due to precession. Hence, electric charge, rest mass and the fine structure constant are interrelated and directly calculable.
1. Atomic structure consists of electrons, protons, and neutrons. Rutherford discovered the nucleus through alpha particle scattering experiments. Bohr proposed electrons orbit the nucleus in discrete energy levels.
2. Millikan's oil drop experiment precisely measured the charge of an electron. J.J. Thomson used cathode ray tubes to discover electrons and determine their small mass.
3. Bohr's model of the hydrogen atom explained its stable orbitals and spectral lines by postulating discrete electron energy levels and angular momentum quantization. This resolved issues with Rutherford's model of unstable orbits.
This document discusses lattice vibrations in solids. It begins by introducing different types of elementary excitations in solids including phonons, which are quantized elastic waves in a crystal. It then describes lattice vibrations as waves that propagate through the crystal as planes of atoms moving in and out of phase. Both longitudinal and transverse polarization of these waves are discussed. Equations of motion are provided and solved to show the wave-like behavior of lattice vibrations. The document also covers phonon dispersion relations, group velocity, Brillouin zones, phonons in diatomic crystals, quantization of elastic waves, phonon momentum, heat capacity of lattices, and early models like Einstein and Debye models to explain temperature-dependent
The document summarizes Niels Bohr's model of the atom from 1913. Bohr proposed that electrons orbit the nucleus in discrete, quantized energy levels. Electrons can jump between these energy levels, absorbing or emitting photons of light. The energy of the photons depends on the energy difference between the initial and final orbit. Bohr's model could only explain the hydrogen atom and failed to account for effects like the Zeeman and Stark effects seen in other atoms. Later developments in quantum mechanics disproved Bohr's idea of electrons having definite orbits.
This document provides an overview of Niels Bohr's atomic model of the hydrogen atom. It describes Bohr's key postulates, including that electrons orbit the nucleus in fixed circular orbits called energy levels, and can only gain or lose energy by jumping between these discrete levels. The model accounted for the observed line spectrum of hydrogen. However, it had limitations and could not explain more complex atoms or effects like the Zeeman effect. It was replaced by later quantum mechanical models.
The document discusses light interaction with atoms and molecules, including:
1) Atomic spectra such as the Balmer series arise from electrons falling to lower energy levels in hydrogen atoms.
2) More complex atoms like sodium and mercury require additional quantum numbers to describe their emission spectra.
3) Simple molecules like hydrogen absorb UV light when electrons are promoted between molecular orbitals.
4) Conjugated systems and heteroatoms in molecules like butadiene and formaldehyde shift absorption to longer wavelengths.
B.Tech sem I Engineering Physics U-IV Chapter 1-ATOMIC PHYSICSAbhi Hirpara
Atomic physics describes phenomena at the scale of atoms and subatomic particles. It emerged in the early 20th century to address limitations in classical physics' ability to describe certain phenomena. Quantum physics recognizes that there is less difference between waves and particles than previously thought. It is probabilistic and counterintuitive, describing particles that can behave as waves and vice versa. Quantum physics underlies our understanding of atomic and subatomic systems and is crucial to fields like chemistry, materials science, and astrophysics. Planck's quantum hypothesis proposed that atoms can only absorb or emit energy in discrete quanta, initiating the development of quantum theory. Einstein later theorized that electromagnetic radiation consists of discrete photon particles, helping explain the photoelectric effect.
Ernest Rutherford's alpha ray scattering experiment led him to propose the nuclear model of the atom. The key findings were:
1) Most alpha particles passed through the thin gold foil with little deflection, but a small percentage were deflected by large angles, including backwards.
2) This could only be explained if the positive charge of the atom was concentrated into a very small, dense nucleus.
3) Rutherford concluded atoms have a small, dense nucleus containing its positive charge and mass, with electrons orbiting the nucleus.
This nuclear model replaced the plum pudding model, but had its own limitations that were later addressed by Niels Bohr's model of electron orbits and quantization
1. The document summarizes the structure and components of an atom according to John Dalton's atomic theory from 1808. Atoms are the smallest indivisible particles of matter and contain subatomic particles like electrons, protons, and neutrons.
2. It describes the properties of these subatomic particles, including their relative masses and electric charges. Electrons were discovered through cathode ray experiments, protons through anode ray experiments, and neutrons by James Chadwick in 1932.
3. The document also summarizes the historical progression of atomic models from Thomson's plum pudding model to Rutherford's nuclear model to Bohr's model of electron orbits to the modern quantum mechanical model developed by Schrodinger and He
Quantum mechanical model of atom belongs to XI standard Chemistry which describes the quantum mechanics concept of atom, quantum numbers, shape and energies of atomic orbitals.
CHAPTER 10 Molecules and Solids
10.1 Molecular Bonding and Spectra
10.2 Stimulated Emission and Lasers
10.3 Structural Properties of Solids
10.4 Thermal and Magnetic Properties of Solids
10.5 Superconductivity
10.6 Applications of Superconductivity
1. The document discusses the development of atomic spectroscopy from 1860 to 1913, including Balmer's empirical formula for the emission spectrum of hydrogen and Bohr's theoretical model of the atom.
2. Bohr postulated that electrons orbit in stable, quantized energy levels and emit or absorb photons of specific frequencies when transitioning between levels.
3. Bohr's model accounted for the Rydberg formula and emission spectrum of hydrogen and was later extended to ions of other elements.
The document discusses key concepts in quantum mechanics including:
1. Photons carry energy and momentum that depends on their frequency or wavelength. Electrons also behave as both particles and waves with an associated wavelength.
2. Heisenberg's uncertainty principle establishes that the more precisely one property of a particle is measured, the less precisely its complementary property can be known.
3. Atomic spectra are unique to each element and arise from electrons transitioning between discrete energy levels in atoms. The wavelength of emitted photons corresponds to energy differences between levels.
Atomic emission spectra and the quantum mechanical model Angbii Gayden
1) Atomic emission spectra provide evidence that electrons within atoms can only occupy discrete energy levels. When electrons drop from higher to lower energy levels, they emit photons of light at specific wavelengths, producing lines in the atomic emission spectrum.
2) Max Planck proposed that electromagnetic radiation like light is emitted and absorbed in discrete quanta of energy called photons, where the energy of each photon is directly proportional to its frequency.
3) Albert Einstein applied Planck's quantum theory to explain the photoelectric effect, proposing that light behaves as a particle as well as a wave, with a quantum of energy depending on its frequency.
This document discusses the development of atomic models. It describes properties of light including its wave-particle duality. The photoelectric effect and hydrogen's emission spectrum provided evidence that light behaves as particles (photons) as well as waves. Max Planck proposed that light energy is quantized in units of hf, where h is Planck's constant and f is the photon's frequency. Niels Bohr's model of the hydrogen atom explained its emission spectrum by proposing that electrons can only orbit at certain distances corresponding to specific energy levels, emitting or absorbing photons as they transition between levels.
The document provides an overview of the key concepts in electronic structure of atoms, including:
1) Light and electromagnetic radiation can be described as waves or particles depending on how they are observed. Max Planck introduced the idea that energy is quantized in discrete units called quanta.
2) Niels Bohr combined classical physics and Planck's quantum theory to develop the Bohr model of the atom, in which electrons orbit the nucleus in fixed energy levels. This explained atomic emission spectra.
3) Later, quantum mechanics developed by Schrodinger, Heisenberg and others described electrons as waves rather than particles. This led to new models of electron orbitals and the filling of these orbitals in
This chapter discusses the evolution of atomic models and the arrangement of electrons in atoms. It covers difficult concepts such as electrons occupying specific energy levels and orbitals. Students are advised to do all assigned homework and bring their textbook to class to fully understand these abstract ideas. Key models discussed include the Rutherford model, the planetary model, Bohr's model linking electrons and photon emission, and the modern quantum mechanical model based on probability.
Structure Of Atom_STUDY MATERIALS_JEE-MAIN_AIPMTSupratim Das
1. Dalton's atomic theory proposed that atoms are indivisible, hard spheres that differ in properties based on their unique structure.
2. Rutherford's gold foil experiment showed that atoms have a small, dense nucleus containing their mass, with electrons orbiting the nucleus.
3. Bohr used Planck's quantum theory to explain electron orbits in hydrogen atoms, stabilizing Rutherford's model and beginning modern atomic theory.
Classical mechanics fails to explain several experimental observations such as:
1) Black-body radiation spectrum
2) Photoelectric effect
3) Compton scattering
4) Spectrum of hydrogen emissions
Quantum mechanics was developed to account for these phenomena by treating electrons as both particles and waves. Max Planck proposed quanta to explain black-body radiation, while Albert Einstein and Niels Bohr used quanta to explain the photoelectric effect and hydrogen spectrum respectively. Arthur Compton also explained Compton scattering using photons colliding with electrons.
This chapter discusses the optical properties of phonons in materials. It covers:
1) Optical and acoustic phonons - some interact directly with light, others cause light scattering.
2) Optical excitation of phonons - how phonons contribute to optical properties through the dielectric function.
3) Phonon polaritons - mixed phonon-photon excitations in crystals near resonance frequencies.
4) Light scattering - concepts of Brillouin, Raman, and Rayleigh scattering involving phonons.
5) Coherent Raman spectroscopy - an experimental technique that enhances weak Raman scattering signals.
A dimensionless quantity described as a fundamental physical constant characterizing the coupling strength of the electromagnetic interaction. Introduced by Sommerfeld in 1916 to describe the spacing of splitting of spectral lines in multi-electron atoms, it is formed from four physical constants: electric charge, speed of light in vacuo, Planck's constant and electric permittivity of free space.
The inverse fine structure constant (=137.035999...) represents the spin precession whirl no. of the electron. The electron exhibits a slight precession due to an imbalance of electrostatic and magnetostatic energy levels. Electric charge is a result of this spin precession and represents a loop closure failure (torsion defect) similar to topological charge.
Rest mass results from quantum wave interference due to precession. Hence, electric charge, rest mass and the fine structure constant are interrelated and directly calculable.
1. Atomic structure consists of electrons, protons, and neutrons. Rutherford discovered the nucleus through alpha particle scattering experiments. Bohr proposed electrons orbit the nucleus in discrete energy levels.
2. Millikan's oil drop experiment precisely measured the charge of an electron. J.J. Thomson used cathode ray tubes to discover electrons and determine their small mass.
3. Bohr's model of the hydrogen atom explained its stable orbitals and spectral lines by postulating discrete electron energy levels and angular momentum quantization. This resolved issues with Rutherford's model of unstable orbits.
This document discusses lattice vibrations in solids. It begins by introducing different types of elementary excitations in solids including phonons, which are quantized elastic waves in a crystal. It then describes lattice vibrations as waves that propagate through the crystal as planes of atoms moving in and out of phase. Both longitudinal and transverse polarization of these waves are discussed. Equations of motion are provided and solved to show the wave-like behavior of lattice vibrations. The document also covers phonon dispersion relations, group velocity, Brillouin zones, phonons in diatomic crystals, quantization of elastic waves, phonon momentum, heat capacity of lattices, and early models like Einstein and Debye models to explain temperature-dependent
The document summarizes Niels Bohr's model of the atom from 1913. Bohr proposed that electrons orbit the nucleus in discrete, quantized energy levels. Electrons can jump between these energy levels, absorbing or emitting photons of light. The energy of the photons depends on the energy difference between the initial and final orbit. Bohr's model could only explain the hydrogen atom and failed to account for effects like the Zeeman and Stark effects seen in other atoms. Later developments in quantum mechanics disproved Bohr's idea of electrons having definite orbits.
This document provides an overview of Niels Bohr's atomic model of the hydrogen atom. It describes Bohr's key postulates, including that electrons orbit the nucleus in fixed circular orbits called energy levels, and can only gain or lose energy by jumping between these discrete levels. The model accounted for the observed line spectrum of hydrogen. However, it had limitations and could not explain more complex atoms or effects like the Zeeman effect. It was replaced by later quantum mechanical models.
The document discusses light interaction with atoms and molecules, including:
1) Atomic spectra such as the Balmer series arise from electrons falling to lower energy levels in hydrogen atoms.
2) More complex atoms like sodium and mercury require additional quantum numbers to describe their emission spectra.
3) Simple molecules like hydrogen absorb UV light when electrons are promoted between molecular orbitals.
4) Conjugated systems and heteroatoms in molecules like butadiene and formaldehyde shift absorption to longer wavelengths.
B.Tech sem I Engineering Physics U-IV Chapter 1-ATOMIC PHYSICSAbhi Hirpara
Atomic physics describes phenomena at the scale of atoms and subatomic particles. It emerged in the early 20th century to address limitations in classical physics' ability to describe certain phenomena. Quantum physics recognizes that there is less difference between waves and particles than previously thought. It is probabilistic and counterintuitive, describing particles that can behave as waves and vice versa. Quantum physics underlies our understanding of atomic and subatomic systems and is crucial to fields like chemistry, materials science, and astrophysics. Planck's quantum hypothesis proposed that atoms can only absorb or emit energy in discrete quanta, initiating the development of quantum theory. Einstein later theorized that electromagnetic radiation consists of discrete photon particles, helping explain the photoelectric effect.
Ernest Rutherford's alpha ray scattering experiment led him to propose the nuclear model of the atom. The key findings were:
1) Most alpha particles passed through the thin gold foil with little deflection, but a small percentage were deflected by large angles, including backwards.
2) This could only be explained if the positive charge of the atom was concentrated into a very small, dense nucleus.
3) Rutherford concluded atoms have a small, dense nucleus containing its positive charge and mass, with electrons orbiting the nucleus.
This nuclear model replaced the plum pudding model, but had its own limitations that were later addressed by Niels Bohr's model of electron orbits and quantization
1. The document summarizes the structure and components of an atom according to John Dalton's atomic theory from 1808. Atoms are the smallest indivisible particles of matter and contain subatomic particles like electrons, protons, and neutrons.
2. It describes the properties of these subatomic particles, including their relative masses and electric charges. Electrons were discovered through cathode ray experiments, protons through anode ray experiments, and neutrons by James Chadwick in 1932.
3. The document also summarizes the historical progression of atomic models from Thomson's plum pudding model to Rutherford's nuclear model to Bohr's model of electron orbits to the modern quantum mechanical model developed by Schrodinger and He
Quantum mechanical model of atom belongs to XI standard Chemistry which describes the quantum mechanics concept of atom, quantum numbers, shape and energies of atomic orbitals.
CHAPTER 10 Molecules and Solids
10.1 Molecular Bonding and Spectra
10.2 Stimulated Emission and Lasers
10.3 Structural Properties of Solids
10.4 Thermal and Magnetic Properties of Solids
10.5 Superconductivity
10.6 Applications of Superconductivity
1. The document discusses the development of atomic spectroscopy from 1860 to 1913, including Balmer's empirical formula for the emission spectrum of hydrogen and Bohr's theoretical model of the atom.
2. Bohr postulated that electrons orbit in stable, quantized energy levels and emit or absorb photons of specific frequencies when transitioning between levels.
3. Bohr's model accounted for the Rydberg formula and emission spectrum of hydrogen and was later extended to ions of other elements.
The document discusses key concepts in quantum mechanics including:
1. Photons carry energy and momentum that depends on their frequency or wavelength. Electrons also behave as both particles and waves with an associated wavelength.
2. Heisenberg's uncertainty principle establishes that the more precisely one property of a particle is measured, the less precisely its complementary property can be known.
3. Atomic spectra are unique to each element and arise from electrons transitioning between discrete energy levels in atoms. The wavelength of emitted photons corresponds to energy differences between levels.
Atomic emission spectra and the quantum mechanical model Angbii Gayden
1) Atomic emission spectra provide evidence that electrons within atoms can only occupy discrete energy levels. When electrons drop from higher to lower energy levels, they emit photons of light at specific wavelengths, producing lines in the atomic emission spectrum.
2) Max Planck proposed that electromagnetic radiation like light is emitted and absorbed in discrete quanta of energy called photons, where the energy of each photon is directly proportional to its frequency.
3) Albert Einstein applied Planck's quantum theory to explain the photoelectric effect, proposing that light behaves as a particle as well as a wave, with a quantum of energy depending on its frequency.
This document discusses the development of atomic models. It describes properties of light including its wave-particle duality. The photoelectric effect and hydrogen's emission spectrum provided evidence that light behaves as particles (photons) as well as waves. Max Planck proposed that light energy is quantized in units of hf, where h is Planck's constant and f is the photon's frequency. Niels Bohr's model of the hydrogen atom explained its emission spectrum by proposing that electrons can only orbit at certain distances corresponding to specific energy levels, emitting or absorbing photons as they transition between levels.
The document provides an overview of the key concepts in electronic structure of atoms, including:
1) Light and electromagnetic radiation can be described as waves or particles depending on how they are observed. Max Planck introduced the idea that energy is quantized in discrete units called quanta.
2) Niels Bohr combined classical physics and Planck's quantum theory to develop the Bohr model of the atom, in which electrons orbit the nucleus in fixed energy levels. This explained atomic emission spectra.
3) Later, quantum mechanics developed by Schrodinger, Heisenberg and others described electrons as waves rather than particles. This led to new models of electron orbitals and the filling of these orbitals in
This chapter discusses the evolution of atomic models and the arrangement of electrons in atoms. It covers difficult concepts such as electrons occupying specific energy levels and orbitals. Students are advised to do all assigned homework and bring their textbook to class to fully understand these abstract ideas. Key models discussed include the Rutherford model, the planetary model, Bohr's model linking electrons and photon emission, and the modern quantum mechanical model based on probability.
Structure Of Atom_STUDY MATERIALS_JEE-MAIN_AIPMTSupratim Das
1. Dalton's atomic theory proposed that atoms are indivisible, hard spheres that differ in properties based on their unique structure.
2. Rutherford's gold foil experiment showed that atoms have a small, dense nucleus containing their mass, with electrons orbiting the nucleus.
3. Bohr used Planck's quantum theory to explain electron orbits in hydrogen atoms, stabilizing Rutherford's model and beginning modern atomic theory.
Classical mechanics fails to explain several experimental observations such as:
1) Black-body radiation spectrum
2) Photoelectric effect
3) Compton scattering
4) Spectrum of hydrogen emissions
Quantum mechanics was developed to account for these phenomena by treating electrons as both particles and waves. Max Planck proposed quanta to explain black-body radiation, while Albert Einstein and Niels Bohr used quanta to explain the photoelectric effect and hydrogen spectrum respectively. Arthur Compton also explained Compton scattering using photons colliding with electrons.
CONTENTS
INTRODUCTION
NEED FOR CYBER LAWS
CYBER LAWS IN INDIA
CYBER CRIMES
OFFENCES AND LAWS IN CYBER SPACE
CYBER LAWS AMENDMENTS
CONCLUSION
INTRODUCTION
What is Cyber Law?
Cyber Law is the lawgoverning cyber space.Cyber space is a very wideterm and includescomputers, networks,software, data storagedevices (such as hard disks,USB disks etc), theInternet, websites, emailsand even electronic devicessuch as cell phones, ATMmachines etc.
Cyber lawencompasses lawsrelating to
:
1. Cyber Crimes
2. Electronic and DigitalSignatures
3. Intellectual Property
4. Data Protection andPrivacy
NEED FOR CYBER LAWS
TACKLING CYBERCRIMES
INTELLECTUALPROPERTYRIGHTS ANDCOPYRIGHTSPROTECTION ACT
NEED FOR CYBER LAWS
1. Cyberspace is an
intangible
dimension that is impossible togovern and regulate usingconventional law.
2. Cyberspace has complete
disrespect for jurisdictionalboundaries
. A person in Indiacould break into a bank’selectronic vault hosted on acomputer in USA and transfermillions of Rupees to anotherbank in Switzerland, all withinminutes. All he would need is alaptop computer and a cellphone.
3. Cyberspace
handlesgigantic traffic volumesevery second
. Billions ofemails are crisscrossing theglobe even as we read this,millions of websites are beingaccessed every minute andbillions of dollars areelectronically transferredaround the world by banksevery day.
4. Cyberspace is
absolutelyopen to participation by all.
A ten year-old in Bhutan canhave a live chat session with aneight year-old in Bali withoutany regard for the distance orthe anonymity between them
ABOUT AUTHOR
Sumit Verma
Chitkara University
Undergraduate
PAPERS
1
FOLLOWERS
575
Follow
RELATED PAPERS
Important question answers Information Technology Act, 2000
Suvo Chatterjee
Download
More Options
IT ACT 2000 – PENALTIES, OFFENCES WITH CASE STUDIES From
aru mugam
Download
More Options
Information Technology
trinisha chakroborty
Download
More Options
OVERVIEW OF CYBER LAWS IN INDIA Index
aneesh tvm
Download
More Options
Critical analysis of proposed cyber Crime Bill 2015
Shahid Jamal T U B R A Z Y Cyber Lawyer
Download
More Options
Final Cyber Cri
Prashant Dabhade
Download
More Options
Cyber Laws in India
Vikas Khatkar
Download
More Options
Commentary on THE INFORMATION TECHNOLOGY ACT, 2000
Rohas Nagpal
Download
More Options
INTRODUCTION TO THE ACT 2. NEED AND OBJECTIVES 3 ROLE OF IT IN ECOMMERCE 4 CYBER CRIME 5 ELECTRONIC SIGNATURES 6 E-GOVERNANCE
keshav agarwal
Download
More Options
NON BAILABLE OFFENCES( Cyber Crimes) UNDER The IT Act, 2000 (Cyber Law)
Adv Prashant Mali, Ph.D.
Download
More Options
P a g e Fundamentals of Cyber Law Rohas Nagpal Asian School of Cyber Laws
vijay onlinesangli
Download
More Options
SEMINAR AND WORKSHOP ON DETECTION OF CYBER CRIME AND INVESTIGATION Presented by
chayapathi A R
Download
More Options
Cyber Crime Investigation and Trial Procedure in Bangladesh: Comparison with India
Thohedul Islam Talukdar
Down
Ernst Goldstein discovered positive rays (protons) in 1886 by passing cathode rays through a perforated cathode. Positive rays were produced and carried a positive charge. J.J. Thomson later determined the e/m ratio of protons depends on the gas used, with hydrogen giving the maximum ratio and identifying the lightest particle as the proton. In 1932, James Chadwick discovered the neutron through bombarding beryllium with alpha particles. The neutron was later found to be neutral and able to induce nuclear reactions. Rutherford proposed atoms consisted of electrons and protons in 1911 based on alpha scattering experiments, but the planetary model was defective as it did not explain the stability of electron orbits.
1) Classical mechanics and Maxwell's equations can explain macroscopic phenomena but quantum mechanics is needed to explain microscopic phenomena such as atomic structure.
2) Quantum mechanics arose from the need to explain physical phenomena not accounted for by classical physics, including blackbody radiation, the photoelectric effect, atomic spectra, and specific heat of solids.
3) Experiments such as the photoelectric effect, Compton effect, diffraction of electrons demonstrated that particles have wave-like properties and waves have particle-like properties, showing the need for a new theoretical framework that incorporated wave-particle duality.
The document discusses the development of atomic models from Dalton to Bohr and beyond. It describes Rutherford's discovery of the nucleus and Bohr's model of electrons in fixed orbits around the nucleus. Later, the quantum mechanical model was developed, restricting electrons to specific energy levels rather than exact orbits. This modern model determines the probability of finding electrons in different locations around the nucleus.
7.1 Atomic, nuclear and particle physicsPaula Mills
This document discusses atomic, nuclear and particle physics concepts including:
- Atomic energy levels and line spectra which provide evidence that electrons can only have certain discrete energy values within an atom.
- The Bohr model of the atom which assumed quantized electron energy levels and explained hydrogen atom spectra.
- Nuclear structure including mass number, nucleons, atomic number, isotopes, and interactions within the nucleus.
- Three types of nuclear radiation - alpha, beta, and gamma rays - and how they differ in their ionizing properties and penetration abilities due to their mass and charge.
- Nuclear stability and how heavier nuclei require more neutrons to counter the repulsive force between protons.
- Two
Chemistry Basic understanding for LIKE WHAT?ArafathIslam4
Dalton's atomic theory proposed that all matter is made of indivisible atoms and that atoms of different elements have different masses. However, later discoveries showed limitations of this theory. Atoms were found to be divisible into subatomic particles and isotopes of the same element can have different masses. Rutherford's gold foil experiment provided evidence that the mass of an atom is concentrated in a small, positively charged nucleus. This led to Rutherford's model of the atom with electrons orbiting the nucleus, like planets around the sun. However, this model could not explain the stability of atoms and quantum theory was needed to fully explain atomic structure.
The document summarizes the development of the atomic model over time based on experimental evidence. It describes J.J. Thomson's discovery of the electron in 1897 and the Plum Pudding model. Rutherford's gold foil experiment in 1911 showed that the atom has a small, dense, positively charged nucleus. The discovery of the proton in 1886 and neutron in 1932 showed that the nucleus contains these particles. Later experiments revealed that electrons orbit in allowed energy levels and quantum numbers were developed to describe these states.
Light travels at 300,000 km/s. It has properties of both waves and particles. Spectral lines identify elements in stars - each element produces a unique set of lines. Astronomers use spectral lines and Wien's and Stefan-Boltzmann laws to determine surface temperatures of stars and planets from their emitted light.
The document discusses the history of atomic structure models from Democritus' idea of atoms to Bohr's model. Some key points:
1. J.J. Thomson's experiments in 1897 led him to propose the "plum pudding" model where electrons were embedded in a uniform positive charge.
2. Rutherford's gold foil experiment in 1911 showed that the atom has a small, dense, positively charged nucleus at its center.
3. Bohr modified Rutherford's model in 1913 to propose that electrons orbit the nucleus in discrete energy levels, explaining atomic line spectra. When electrons fall from higher to lower orbits, photons are emitted.
This document provides a summary of key concepts about electrons in atoms, including:
1) It discusses the evolution of atomic models from Rutherford to Bohr, focusing on explaining the arrangement of electrons. The quantum mechanical model describes electron probability clouds rather than fixed orbits.
2) It covers atomic orbitals and how electrons fill different orbitals based on their principal and angular momentum quantum numbers. Higher principal quantum numbers correspond to higher energy levels further from the nucleus.
3) The document emphasizes that electrons fill orbitals based on the Aufbau principle to achieve the lowest possible energy configuration. Understanding electron configurations is essential to describing elements and their properties.
Quantum Mechanics: Electrons, Transistors, & LASERS. Paul H. Carr
Quantum Mechanics, QM, has enabled new technologies that impact our daily lives. Yet, there have been at least 14 different QM interpretations in the last century. “If you think you understand QM, you don’t,” said Richard Feynman. Our macroscopic language is inadequate to describe the wave-particle duality of microscopic QM particles. Mathematics works better. This talk illuminated the production of the play Copenhagen, in which German physicist Werner Heisenberg, who directed the German attempt to make an atom bomb, visited Niels Bohr in Denmark during WWII.
The document discusses atomic structure and models of the atom. It describes J.J. Thomson's discovery of the electron and the plum pudding model. It then summarizes Rutherford's gold foil experiment, which led to the nuclear model of the atom with a small, dense nucleus surrounded by electrons. The document also discusses atomic spectra and how they provided evidence for discrete energy levels of electrons within atoms.
This document provides an overview of key topics in early quantum theory that students should understand, including:
- Electrons, J.J. Thompson's experiment determining the electron, and Millikan's experiment measuring the charge of an electron.
- De Broglie's relation connecting the wavelength of a particle to its momentum.
- Wave-particle duality and the principle of complementarity established by Bohr.
- That matter can behave as waves according to de Broglie's theory of the dual nature of matter.
- Planck's quantum hypothesis that the energy of atomic oscillations is quantized in integer multiples of Planck's constant.
This document provides an overview of key topics in early quantum theory that students should understand, including:
- Electrons, J.J. Thompson's experiment determining the electron, and Millikan's experiment measuring the charge of an electron.
- De Broglie's relation connecting the wavelength of a particle to its momentum.
- Wave-particle duality and the principle of complementarity stating that particles can behave as both waves and particles.
- Planck's quantum hypothesis that the energy of atomic oscillations is quantized in integer multiples of Planck's constant.
1. Light was originally thought to be particles but experiments showed it exhibited wave-like properties. Maxwell unified electricity, magnetism and light by describing light as electromagnetic waves. Planck explained blackbody radiation by quantizing light into discrete "quanta" called photons, showing light has both wave and particle properties.
2. The photoelectric effect and double slit experiments further supported the dual nature of light. De Broglie hypothesized that if light acts as particles then particles should act as waves, which was confirmed. Heisenberg's uncertainty principle emerged from this understanding.
3. Lasers exploit stimulated emission to produce intense, coherent beams of light. Applications include microscopy, which uses lasers' tunability and focusing
1. Light was originally thought to be particles but experiments showed it exhibited wave-like properties. Maxwell unified electricity, magnetism and light by describing light as electromagnetic waves. Planck explained blackbody radiation by quantizing light into discrete "quanta" called photons, showing light has both wave and particle properties.
2. The photoelectric effect and double slit experiments further supported the dual nature of light. De Broglie hypothesized that if light acts as particles then particles should act as waves, which was confirmed. Heisenberg's uncertainty principle emerged from this understanding.
3. Lasers exploit stimulated emission to produce intense, coherent beams of light. Applications include microscopy, which overcomes the diffraction limit using techniques like
The document discusses various microbiology techniques for culturing microbes including inoculation, isolation, incubation, inspection, and identification. It describes how to produce pure cultures through methods like streak plating and describes different types of culture media including solid, liquid, enriched, selective, and differential media. The goals are to transfer microbes to produce isolated colonies, grow them under proper conditions, observe characteristics, and identify organisms through comparing data.
The document provides instructions for creating a research poster, including reviewing sample posters and an article on best practices. It discusses font size, logo placement, poster size, image and graphic quality, and elements that make a poster engaging. A sample student research poster is also included, with sections on the problem, methodology, results, conclusions, and references. The poster summarizes a study on the occupations of school-aged children who have siblings with cognitive or behavioral disabilities.
The document provides instructions for creating an effective research poster. It discusses reviewing sample posters to understand best practices like font size, logo placement, size of the poster, and quality of images. It also recommends considering what makes sample posters visually engaging and how one's own poster could be improved.
Position Your Body for Learning implements evidence-based measurements to assess optimal positioning for learning. The document describes three simple assessments - "roll", "rattle", and "rumble" - to determine if desk height matches elbow rest height and chair height matches popliteal height. It explains that proper ergonomic positioning through adjustments can improve students' attention, fine motor skills, and performance on standardized tests. The document provides a form called "Measuring for Optimal Positioning" to document student measurements and identify furniture adjustments needed.
The agenda outlines a thesis dissemination meeting that will include welcome and introductions, a syllabus review, project summaries from students, breaks, a presentation on APA style and thesis document preparation from the writing center, library resources overview, and discussion of thesis resources and dismissal. The document also lists various thesis course, poster, article, and conference resources that will be made available to students.
This document discusses program evaluation, outlining key concepts and approaches. It describes the purposes of program evaluation as determining if objectives are met and improving decision making. Formative and summative evaluations are explained, with formative used for ongoing improvement and summative to determine effects. Both quantitative and qualitative methods are appropriate, including experimental, quasi-experimental and non-experimental designs. Stakeholder involvement, utilization of results, and addressing ethical considerations are important aspects of program evaluation.
The document outlines topics from Chapter 6 of a course, including similarities and differences between intervention planning for individuals and community programs, best practices for developing mission statements and effective teams, and issues related to program sustainability. It also provides examples and activities for developing SMART goals, vision and mission statements, and sustainability plans for a fall prevention program. Resources and considerations are presented for each step of the program development process.
Compliance, motivation, and health behaviors stanbridge
This document provides information about compliance, motivation, and health behaviors as they relate to learners. It introduces several occupational therapy students and their backgrounds. The objectives cover defining key terms and discussing theories of compliance, motivation concepts, and strategies to facilitate motivation. The document then matches vocabulary terms to their definitions and discusses several theories of behavior change, including the health belief model, self-efficacy theory, protection motivation theory, stages of change model, and theory of reasoned action. Motivational strategies and the educator's role in health promotion are also outlined.
Ch 5 developmental stages of the learnerstanbridge
This document provides an overview of developmental stages of the learner from infancy through older adulthood. It begins with introductions of the presenters and learning objectives. Key terms are defined. Development is discussed in terms of physical, cognitive, and psychosocial characteristics at each stage: infancy/toddlerhood, early childhood, middle/late childhood, adolescence, young adulthood, middle-aged adulthood, and older adulthood. Teaching strategies are outlined for each developmental stage. The role of family in patient education is also addressed.
This document summarizes the content covered in Week 2 of a course on community-based occupational therapy practice. Chapter 3 discusses using theories from related disciplines in community practice and identifying strategies for organizing communities to meet health needs. Chapter 4 covers understanding relevant federal legislation, including laws supporting reimbursement and those focused on education, medical rehabilitation, consumer rights, and environmental issues. The document also lists vocabulary terms and guest speakers for the week.
This document outlines the topics and activities to be covered in Week 3 of a course on community health and health promotion program development. It will describe processes of environmental scanning, trend analysis, and the key steps of community health program development. Students will learn about needs assessments, theories in health promotion planning, goals and objectives, and the ecological approach. They will develop implementation strategies at different levels of intervention and learn the purposes of program evaluation. Readings, discussions, and activities are planned, including a scenario analyzing a sheltered workshop using SWOT analysis. Key terms and concepts are defined.
This document outlines the topics that will be covered in the first two chapters of a course on community-based occupational therapy practice. Chapter 1 will discuss the history and roles of OT in community-based practice as well as characteristics of effective community-based OTs. It will also cover paradigm shifts in OT. Chapter 2 will address concepts in community and public health, determinants of health, and strategies for prevention. It will discuss OT's contributions to Healthy People 2020 and its role in health promotion. The schedule includes lectures, small group work, and a guest speaker.
This document discusses how to critically appraise quantitative studies for clinical decision making. It covers evaluating the validity, reliability, and applicability of studies. Key points include assessing for bias, determining if results are statistically and clinically significant, and considering how well study findings can be applied to patients. Study designs like randomized controlled trials, case-control studies, and cohort studies are examined. The importance of systematic reviews and meta-analyses in evidence-based practice is also covered.
This document discusses the importance of clinical judgment in evidence-based nursing practice. It states that research evidence must be considered alongside patient concerns and preferences. Good clinical judgment requires carefully examining the validity of evidence and how it is applied to specific patients. The fit between evidence and each patient's unique situation is rarely perfect. Nurses must understand patients narratively and use judgment over time to determine the most appropriate care based on evidence and the patient's needs. Experiential learning and developing expertise in caring for particular patient populations enhances a nurse's clinical grasp and judgment.
This document discusses qualitative research and its application to clinical decision making. It describes how qualitative evidence can inform understanding of patient experiences and perspectives, which are important components of evidence-based practice. The document outlines different qualitative research traditions like ethnography, grounded theory, and phenomenology. It also discusses techniques for appraising qualitative studies based on their credibility, transferability, dependability, and confirmability. The key point is that qualitative evidence provides insights into human experiences, values, and meanings that can help inform clinical decisions.
This document discusses critically appraising knowledge for clinical decision making. It explains that practice should be based on unbiased, reliable evidence rather than tradition. The three main sources of knowledge for evidence-based practice are valid research evidence, clinical expertise, and patient choices. Clinical practice guidelines are the primary source to guide decisions as they synthesize research evidence. Internal evidence from quality improvement projects applies specifically to the setting where it was collected, unlike external evidence which is more generalizable. Both internal and external evidence should be combined using the PDSA (Plan-Do-Study-Act) cycle for continuous improvement.
This document discusses implementing evidence-based practice (EBP) in clinical settings. It emphasizes that engaging all stakeholders, including clinical staff, administrators, and other disciplines, is key. It also stresses that assessing and addressing barriers like knowledge, attitudes, and resources is important. Finally, it highlights that evaluating outcomes through quantifiable measures can help determine the impact of EBP changes on patient care.
This document discusses clinical practice guidelines (CPGs), including how they are developed based on evidence, how they can standardize care while allowing flexibility, and how to evaluate and implement them. It notes that CPGs systematically develop statements to guide regional diagnosis and treatment based on the best available evidence. While CPGs provide time-effective guidance, the commitment of caregivers is most important for successful implementation.
This document discusses key aspects of writing a successful grant proposal. It explains that grant proposals request funding for research or evidence-based projects by outlining specific aims, background, significance, methodology, budget, and personnel. Successful grant writers are passionate, meticulous planners who can persuade reviewers of a project's importance and address potential barriers. The most important initial question is whether a project meets the funding organization's application criteria. Proposals need compelling abstracts that explain why a project deserves funding and clearly written background and methodology sections. Common weaknesses that can lead to rejection are a lack of significance or novel ideas and inadequate description of study design.
The document discusses ethical considerations for evidence implementation and generation in healthcare. It outlines key ethical principles like beneficence, nonmaleficence, autonomy and justice. These principles form the foundation for core dimensions of healthcare quality according to the Institute of Medicine. The document also differentiates between clinical research, quality improvement initiatives, and evidence-based practice. It notes some controversies around applying different ethical standards to research versus quality improvement. Overall, the document provides an overview of how ethical principles guide evidence-based healthcare practices and quality improvement efforts.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/building-and-scaling-ai-applications-with-the-nx-ai-manager-a-presentation-from-network-optix/
Robin van Emden, Senior Director of Data Science at Network Optix, presents the “Building and Scaling AI Applications with the Nx AI Manager,” tutorial at the May 2024 Embedded Vision Summit.
In this presentation, van Emden covers the basics of scaling edge AI solutions using the Nx tool kit. He emphasizes the process of developing AI models and deploying them globally. He also showcases the conversion of AI models and the creation of effective edge AI pipelines, with a focus on pre-processing, model conversion, selecting the appropriate inference engine for the target hardware and post-processing.
van Emden shows how Nx can simplify the developer’s life and facilitate a rapid transition from concept to production-ready applications.He provides valuable insights into developing scalable and efficient edge AI solutions, with a strong focus on practical implementation.
Building Production Ready Search Pipelines with Spark and MilvusZilliz
Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
Essentials of Automations: The Art of Triggers and Actions in FMESafe Software
In this second installment of our Essentials of Automations webinar series, we’ll explore the landscape of triggers and actions, guiding you through the nuances of authoring and adapting workspaces for seamless automations. Gain an understanding of the full spectrum of triggers and actions available in FME, empowering you to enhance your workspaces for efficient automation.
We’ll kick things off by showcasing the most commonly used event-based triggers, introducing you to various automation workflows like manual triggers, schedules, directory watchers, and more. Plus, see how these elements play out in real scenarios.
Whether you’re tweaking your current setup or building from the ground up, this session will arm you with the tools and insights needed to transform your FME usage into a powerhouse of productivity. Join us to discover effective strategies that simplify complex processes, enhancing your productivity and transforming your data management practices with FME. Let’s turn complexity into clarity and make your workspaces work wonders!
GraphSummit Singapore | The Art of the Possible with Graph - Q2 2024Neo4j
Neha Bajwa, Vice President of Product Marketing, Neo4j
Join us as we explore breakthrough innovations enabled by interconnected data and AI. Discover firsthand how organizations use relationships in data to uncover contextual insights and solve our most pressing challenges – from optimizing supply chains, detecting fraud, and improving customer experiences to accelerating drug discoveries.
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
Why You Should Replace Windows 11 with Nitrux Linux 3.5.0 for enhanced perfor...SOFTTECHHUB
The choice of an operating system plays a pivotal role in shaping our computing experience. For decades, Microsoft's Windows has dominated the market, offering a familiar and widely adopted platform for personal and professional use. However, as technological advancements continue to push the boundaries of innovation, alternative operating systems have emerged, challenging the status quo and offering users a fresh perspective on computing.
One such alternative that has garnered significant attention and acclaim is Nitrux Linux 3.5.0, a sleek, powerful, and user-friendly Linux distribution that promises to redefine the way we interact with our devices. With its focus on performance, security, and customization, Nitrux Linux presents a compelling case for those seeking to break free from the constraints of proprietary software and embrace the freedom and flexibility of open-source computing.
In his public lecture, Christian Timmerer provides insights into the fascinating history of video streaming, starting from its humble beginnings before YouTube to the groundbreaking technologies that now dominate platforms like Netflix and ORF ON. Timmerer also presents provocative contributions of his own that have significantly influenced the industry. He concludes by looking at future challenges and invites the audience to join in a discussion.
Let's Integrate MuleSoft RPA, COMPOSER, APM with AWS IDP along with Slackshyamraj55
Discover the seamless integration of RPA (Robotic Process Automation), COMPOSER, and APM with AWS IDP enhanced with Slack notifications. Explore how these technologies converge to streamline workflows, optimize performance, and ensure secure access, all while leveraging the power of AWS IDP and real-time communication via Slack notifications.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und überflüssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
Full-RAG: A modern architecture for hyper-personalizationZilliz
Mike Del Balso, CEO & Co-Founder at Tecton, presents "Full RAG," a novel approach to AI recommendation systems, aiming to push beyond the limitations of traditional models through a deep integration of contextual insights and real-time data, leveraging the Retrieval-Augmented Generation architecture. This talk will outline Full RAG's potential to significantly enhance personalization, address engineering challenges such as data management and model training, and introduce data enrichment with reranking as a key solution. Attendees will gain crucial insights into the importance of hyperpersonalization in AI, the capabilities of Full RAG for advanced personalization, and strategies for managing complex data integrations for deploying cutting-edge AI solutions.
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
Maruthi Prithivirajan, Head of ASEAN & IN Solution Architecture, Neo4j
Get an inside look at the latest Neo4j innovations that enable relationship-driven intelligence at scale. Learn more about the newest cloud integrations and product enhancements that make Neo4j an essential choice for developers building apps with interconnected data and generative AI.
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
Threats to mobile devices are more prevalent and increasing in scope and complexity. Users of mobile devices desire to take full advantage of the features
available on those devices, but many of the features provide convenience and capability but sacrifice security. This best practices guide outlines steps the users can take to better protect personal devices and information.
Best 20 SEO Techniques To Improve Website Visibility In SERPPixlogix Infotech
Boost your website's visibility with proven SEO techniques! Our latest blog dives into essential strategies to enhance your online presence, increase traffic, and rank higher on search engines. From keyword optimization to quality content creation, learn how to make your site stand out in the crowded digital landscape. Discover actionable tips and expert insights to elevate your SEO game.
2. Classical physics (Newtonian physics) – development of
physics prior to around 1900
Classical physics was generally concerned with macrocosm –
the description & explanation of large-scale phenomena
◦ cannon balls, planets, wave motion, sound, optics,
electromagnetism
Modern physics (after about 1900) – concerned with the
microscopic world – microcosm – the subatomic world is
difficult to describe with classical physics
This chapter deals with only a part of modern physics called
Atomic Physics – dealing with electrons in the atom.
Section 9.1
3. Greek Philosophers (400 B.C.) debated whether
matter was continuous or discrete, but could prove
neither.
◦ Continuous – could be divided indefinitely
◦ Discrete – ultimate indivisible particle
◦ Most (including Aristotle) agreed with the continuous
theory.
The continuous model of matter prevailed for 2200
years, until 1807.
Section 9.1
4. In 1807 John Dalton presented evidence that
matter was discrete and must exist as particles.
Dalton’s major hypothesis stated that:
Each chemical element is composed of small
indivisible particles called atoms,
◦ identical for each element but different from atoms of
other elements
Essentially these particles are featureless spheres
of uniform density.
Section 9.1
5. Dalton’s 1807 “billiard
ball model”
pictured the atom as a
tiny indivisible,
uniformly dense, solid
sphere.
Section 9.1
6. In 1903 J.J. Thomson discovered the electron.
Further experiments by Thomson and others
showed that an electron has a mass of 9.11 x 10-31
kg and a charge of –1.60 x 10-19
C.
Thomson produced ‘rays’ using several different
gas types in cathode-ray tubes.
◦ He noted that these rays were deflected by electric and
magnetic fields.
Thomson concluded that this ray consisted of
negative particles (now called electrons.)
Section 9.1
7. Identical electrons were produced no matter what
gas was in the tube.
Therefore he concluded that atoms of all types
contained ‘electrons.’
Since atoms as a whole are electrically neutral,
some other part of the atom must be positive.
Thomson concluded that the electrons were stuck
randomly in an otherwise homogeneous mass of
positively charged “pudding.”
Section 9.1
8. Thomson’s 1903
“plum pudding
model”
conceived the
atom as a sphere
of positive charge
in which negatively
charged electrons
were embedded.
Section 9.1
9. In 1911 Rutherford discovered that 99.97% of the
mass of an atom was concentrated in a tiny core,
or nucleus.
Rutherford’s model envisioned the electrons as
circulating in some way around a positively
charged core.
Section 9.1
10. Rutherford’s 1911
“nuclear model”
envisioned the
atom as having a
dense center of
positive charge (the
nucleus) around
which the electrons
orbited.
Section 9.1
12. Scientists have known for many centuries that
very hot (or incandescent) solids emit visible light
◦ Iron may become “red” hot or even “white” hot, with
increasing temperature
◦ The light that common light bulbs give off is due to the
incandescence of the tungsten filament
This increase in emitted light frequency is
expected because as the temperature increases
the greater the electron vibrations and ∴ the
higher frequency of the emitted radiation
Section 9.2
14. As the temperature
increases the peak
of maximum
intensity shifts to
higher frequency –
it goes from red to
orange to white hot.
Wave theory
correctly predicts
this.
Section 9.2
15. According to
classical wave
theory, I α f 2
. This
would mean that I
should increase
rapidly
(exponentially) with
an increase in f.
This is NOT what
is actually
observed.
Section 9.2
16. Since classical wave could not explain why the
relationship I α f 2
is not true, this dilemma was
coined the “ultraviolet catastrophe”
“Ultraviolet” because the relationship broke down at high
frequencies.
And “catastrophe” because the predicted energy
intensity fell well short.
The problem was resolved in 1900 by Max Planck,
a German physicist
Section 9.2
17. In 1900 Planck introduced the idea of a quantum –
an oscillating electron can only have discrete, or
specific amounts of energy
Planck also said that this amount of energy (E)
depends on its frequency ( f )
Energy = Planck’s constant x frequency (E = hf )
This concept by Planck took the first step toward
quantum physics
Section 9.2
18. Planck’s hypothesis correctly accounted for the
observed intensity with respect to the frequency
squared
Therefore Planck introduce the idea of the
“quantum” – a discrete amount of energy
◦ Like a “packet” of energy
Similar to the potential energy of a person on a
staircase – they can only have specific potential-
energy values, determined by the height of each
stair
Section 9.2
20. Scientists noticed that certain metals emitted
electrons when exposed to light– The
photoelectric effect
This direct conversion of light into electrical
energy is the basis for photocells
◦ Automatic door openers, light meters, solar energy
applications
Once again classical wave theory could not
explain the photoelectric effect
Section 9.2
21. In classical wave theory it should take an
appreciable amount of time to cause an electron
to be emitted
But … electrons flow is almost immediate when
exposed to light
Thereby indicating that light consists of “particles”
or “packets” of energy
Einstein called these packets of energy “photons”
Section 9.2
23. In addition, it was shown that the higher the
frequency the greater the energy
◦ For example, blue light has a higher frequency than red
light and therefore have more energy than photons of
red light.
In the following two examples you will see that
Planck’s Equation correctly predict the relative
energy levels of red and blue light
Section 9.2
24. Find the energy in joules of the photons of red
light of frequency 5.00 x 1014
Hz (cycles/second)
You are given: f and h (Planck’s constant)
Use Planck’s equation E = hf
E = hf = (6.63 x 10-34
J s)(5.00 x 1014
/sec)
= 33.15 x 10-20
J
Section 9.2
25. Find the energy in joules of the photons of blue
light of frequency 7.50 x 1014
Hz (cycles/second)
You are given: f and h (Planck’s constant)
Use Planck’s Equation E = hf
E = hf = (6.63 x 10-34
J s)(7.50 x 1014
/sec)
= 49.73 x 10-20
J
** Note the blue light has more energy than red light
Section 9.2
26. To explain various phenomena, light sometimes
must be described as a wave and sometimes as a
particle.
Therefore, in a specific experiment, scientists use
whichever model (wave or particle theory) of light
works!!
Apparently light is not exactly a wave or a particle,
but has characteristics of both
In the microscopic world our macroscopic
analogies may not adequately fit
Section 9.2
27. Recall from chapter 7 that white light can be
dispersed into a spectrum of colors by a prism
◦ Due to differences in refraction for the specific
wavelengths
In the late 1800’s experimental work with gas-
discharge tubes revealed two other types of
spectra
◦ Line emission spectra displayed only spectral lines of
certain frequencies
◦ Line absorption spectra displays dark lines of missing
colors
Section 9.3
29. When light from a gas-discharge tube is analyzed only
spectral lines of certain frequencies are found
Section 9.3
30. Results in dark lines (same as the bright lines of the line
emission spectrum) of missing colors.
Section 9.3
31. Spectroscopists did not initially understand why
only discrete, and characteristic wavelengths of
light were
◦ Emitted in a line emission spectrum, and
◦ Omitted in a line absorption spectrum
In 1913 an explanation of the observed spectral
line phenomena was advanced by the Danish
physicist Niels Bohr
Section 9.3
32. Bohr decided to study the hydrogen atom because
it is the simplest atom
◦ One single electron “orbiting” a single proton
As most scientists before him, Bohr assumed that
the electron revolved around the nuclear proton –
but…
Bohr correctly reasoned that the characteristic
(and repeatable) line spectra were the result of a
“quantum effect”
Section 9.3
33. Bohr predicted that the single hydrogen electron
would only be found in discrete orbits with
particular radii
◦ Bohr’s possible electron orbits were given whole-
number designations, n = 1, 2, 3, …
◦ “n” is called the principal quantum number
◦ The lowest n-value, (n = 1) has the smallest radii
Section 9.3
34. Each possible electron
orbit is characterized
by a quantum number.
Distances from the
nucleus are given in
nanometers.
Section 9.3
35. Classical atomic theory indicated that an
accelerating electron should continuously radiate
energy
◦ But this is not the case
◦ If an electron continuously lost energy, it would soon
spiral into the nucleus
Bohr once again correctly hypothesized that the
hydrogen electron only radiates/absorbs energy
when it makes an quantum jump or transition to
another orbit
Section 9.3
36. A transition to a lower
energy level results in
the emission of a
photon.
A transition to a higher
energy level results in
the absorption of a
photon.
Section 9.3
37. According to the Bohr model the “allowed orbits”
of the hydrogen electron are called energy states
or energy levels
◦ Each of these energy levels correspond to a specific
orbit and principal quantum number
In the hydrogen atom, the electron is normally at n
= 1 or the ground state
The energy levels above the ground state (n = 2,
3, 4, …) are called excited states
Section 9.3
38. Note that the
energy levels are
not evenly
spaced.
Section 9.3
39. If enough energy is applied, the electron will no
longer be bound to the nucleus and the atom is
ionized
As a result of the mathematical development of
Bohr’s theory, scientists are able to predict the
radii and energies of the allowed orbits
For hydrogen, the radius of a particular orbit can
be expressed as
◦ rn = 0.053 n2
nm
n = principal quantum number of an orbit
r = orbit radius
Section 9.3
40. Determine the radius in nm of the second orbit (n
= 2, the first excited state) in a hydrogen atom
Solution:
Use equation 9.2 rn = 0.053 n2
nm
n = 2
r1 = 0.053 (2)2
nm = 0.212 nm
Same value as Table 9.1!
Section 9.3
41. The total energy of the hydrogen electron in an
allowed orbit is given by the following equation:
En = -13.60/n2
eV (eV = electron volts)
The ground state energy value for the hydrogen
electron is –13.60 eV
◦ ∴ it takes 13.60 eV to ionize a hydrogen atom
◦ the hydrogen electron’s binding energy is 13.60 eV
Note that as the n increases the energy levels
become closer together
Section 9.3
42. Determine the energy of an electron in the first
orbit (n = 1, the ground state) in a hydrogen atom
Solution:
Use equation 9.3 En = -13.60/n2
eV
n = 1
En = -13.60/(1)2
eV = -13.60 eV
Same value as Table 9.1!
Section 9.3
43. Determine the energy of an electron in the first
orbit (n = 2, the first excited state) in a hydrogen
atom
Solution:
Use equation 9.3 En = -13.60/n2
eV
n = 2
En = -13.60/(2)2
eV = -3.40 eV
Same value as Table 9.1!
Section 9.3
44. Recall that Bohr was trying to explain the discrete
line spectra as exhibited in the -
◦ Line Emission & Line Absorption spectrum
◦ Note that the observed and omitted spectra
coincide!
Line Absorption Spectra
Section 9.3
Line Emission Spectra
45. The hydrogen line emission spectrum results from
the emission of energy as the electron de-excites
◦ Drops to a lower orbit and emits a photon
The hydrogen line absorption spectrum results
from the absorption of energy as the electron is
excited
◦ Jumps to a higher orbit and absorbs a photon
Section 9.3
46. The dark lines in the hydrogen line absorption
spectrum exactly matches up with the bright lines
in the hydrogen line emission spectrum
Therefore, the Bohr hypothesis correctly predicts
that an excited hydrogen atom will emit/absorb
light at the same discrete frequencies/amounts,
depending upon whether the electron is being
excited or de-excited
Section 9.3
47. Transitions among
discrete energy orbit
levels give rise to
discrete spectral lines
within the UV, visible,
and IR wavelengths
Section 9.3
48. Energy level arrangements are different for all of
the various atoms
Therefore every element has a characteristic and
unique line emission and line absorption
“fingerprints”
In 1868 a dark line was found in the solar
spectrum that was unknown at the time
◦ It was correctly concluded that this line represented a
new element – named helium
◦ Later this element was indeed found on earth
Section 9.3
49. Modern Physics and Chemistry actively study the
energy levels of various atomic and molecular
systems
◦ Molecular Spectroscopy is the study of the spectra and
energy levels of molecules
As you might expect, molecules of individual
substances produce unique and varied spectra
For example, the water molecule has rotational
energy levels that are affected and changed by
microwaves
Section 9.3
51. Because most foods contain moisture, their water
molecules absorb the microwave radiation and
gain energy
◦ As the water molecules gain energy, they rotate more
rapidly, thus heating/cooking the item
◦ Fats and oils in the foods also preferentially gain energy
from (are excited by) the microwaves
Section 9.4
52. Paper/plastic/ceramic/glass dishes are not directly
heated by the microwaves
◦ But may be heated by contact with the food
(conduction)
The interior metal sides of the oven reflect the
radiation and remain cool
Do microwaves penetrate the food and heat it
throughout?
◦ Microwaves only penetrate a few centimeters and
therefore they work better if the food is cut into small
pieces
◦ Inside of food must be heated by conduction
Section 9.4
53. In 1946 a Raytheon Corporation engineer, Percy
Spencer, put his chocolate bar too close to a
microwave source
The chocolate bar melted of course, and …
Within a year Raytheon introduced the first
commercial microwave oven!
Section 9.4
54. Accidentally discovered in 1895 by the German
physicist Wilhelm Roentgen
◦ He noticed while working with a gas-discharge tube that
a piece of fluorescent paper across the room was
glowing
Roentgen deduced that some unknown/unseen
radiation from the tube was the cause
◦ He called this mysterious radiation “X-radiation”
because it was unknown
Section 9.4
55. Electrons from the cathode are accelerated
toward the anode. Upon interacting with the
atoms of the anode, the atoms emit energy in the
form of x-rays.
Section 9.4
56. Within few months of their
discovery, X-rays were
being put to practical use.
This is an X-ray of bird
shot embedded in a hand.
Unfortunately, much of the
early use of X-rays was
far too aggressive,
resulting in later cancer.
Section 9.4
57. Unlike the accidental discovery of X-rays, the idea
for the laser was initially developed from theory
and only later built
The word laser is an acronym for
◦ Light Amplification by Stimulated Emission of Radiation
Most excited atoms will immediately return to
ground state, but …
Some substances (ruby crystals, CO2 gas, and
others) have metastable excited states
Section 9.4
58. An atom absorbs a photon and becomes excited
(transition to a higher orbit)
Section 9.4
59. Generally the excited atom immediately returns to
ground state, emitting a photon
Section 9.4
60. Striking an excited atom with a photon of the
same energy as initially absorbed will result in the
emission of two photons
Section 9.4
61. a) Electrons absorb energy and
move to higher level
b) Photon approaches and
stimulate emission occurs
c) Stimulated emission chain
reaction occurs
Section 9.4
62. In a stimulated emission an excited atom is struck
by a photon of the same energy as the allowed
transition, and two photons are emitted
The two photon are in phase and therefore
constructively interfere
The result of many stimulated emissions and
reflections in a laser tube is a narrow, intense
beam of laser light
◦ The beam consists of the same energy and wavelength
(monochromatic)
Section 9.4
63. Very accurate measurements can be made by
reflecting these narrow laser beams
◦ Distance from Earth to the moon
◦ Between continents to determine rate of plate
movement
Communications, Medical, Industrial, Surveying,
Photography, Engineering
A CD player reads small dot patterns that are
converted into electronic signals, then sound
Section 9.4
64. In 1927 the German physicist introduced a new
concept relating to measurement accuracy.
Heisenberg’s Uncertainty Principle can be stated
as: It is impossible to know a particle’s exact
position and velocity simultaneously.
Section 9.5
65. Suppose one is interested in the exact position
and velocity of and electron.
At least one photon must bounce off the electron
and come to your eye.
The collision process between the photon and the
electron will alter the electron’s position or
velocity.
Section 9.5
67. Further investigation led to the conclusion that
several factors need to be considered in
determining the accuracy of measurement:
◦ Mass of the particle (m)
◦ Minimum uncertainty in velocity (∆v)
◦ Minimum uncertainty in position (∆x)
When these three factors are multiplied together
they equal a very small number.
◦ Close to Planck’s constant (h = 6.63 10-34
J.
s)
Section 9.5
68. Therefore: m(∆v)(∆x) ≅ h
Although this principle may be philosophically
significant, it is only of practical importance when
dealing with particles of atomic and subatomic
size.
Section 9.5
69. With the development of the dual nature of light it
became apparent that light “waves” sometime act
like particles.
Could the reverse be true?
Can particles have wave properties?
In 1925 the French physicist de Broglie postulated
that matter has properties of both waves and
particles.
Section 9.6
70. Any moving particle has a wave associated with it
whose wavelength is given by the following
formula
λ = h/mv
λ = wavelength of the moving particle
m = mass of the moving particle
v = speed of the moving particle
h = Planck’s constant (6.63 x 10-34
J.
s)
Section 9.6
71. The waves associated with moving particles are
called matter waves or de Broglie waves.
Note in de Broglie’s equation (λ = h/mv) the
wavelength (λ) is inversely proportional to the
mass of the particle (m)
Therefore the longest wavelengths are associated
with particles of very small mass.
Also note that since h is so small, the resulting
wavelengths of matter are also quite small.
Section 9.6
72. Find the de Broglie wavelength for an electron (m
= 9.11 x 10-31
kg) moving at 7.30 x 105
m/s.
Use de Broglie equation: λ = h/mv
We are given h, m, & v
=λ
6.63 x 10-34
Js
(9.11 x 10-31
kg)(7.30 x 105
m/s)
Section 9.6
73. λ = 1.0 x 10-9
m = 1.0 nm (nanometer)
This wavelength is only several times larger than the
diameter of the average atom, therefore significant
for an electron.
=λ
6.63 x 10-34
kg m2
s/s2
(9.11 x 10-31
kg)(7.30 x 105
m/s)
Section 9.6
74. Find the de Broglie wavelength for a 1000 kg car
traveling at 25 m/s
Use de Broglie equation: λ = h/mv
We are given h, m, & v
λ = 2.65 x 10–38
m = 2.65 x 10-29
nm
A very short wavelength!
=λ 6.63 x 10-34
Js
(1000 kg)(25 m/s)
=
6.63 x 10-34
kg m2
s/s2
(1000 kg)(25 m/s)
Section 9.6
75. In 1927 two U.S. scientists, Davisson and Germer,
experimentally verified that particles have wave
characteristics.
These two scientists showed that a bean of
electrons (particles) exhibits a diffraction pattern
(a wave property.)
Recall Section 7.4 – appreciable diffraction only
occurs when a wave passes through a slit of
approximately the same width as the wavelength
Section 9.6
76. Recall from our Exercise Example that an electron
would be expected to have a λ ≅ 1 nm.
Slits in the range of 1 nm cannot be manufactured
BUT … nature has already provided us with
suitably small “slits” in the form of mineral crystal
lattices.
By definition the atoms in mineral crystals are
arranged in an orderly and repeating pattern.
Section 9.6
77. The orderly rows within a crystal lattice provided
the extremely small slits needed (in the range of 1
nm.)
Davisson and Germer photographed two
diffraction patterns.
◦ One pattern was made with X-rays (waves) and one
with electrons (particles.)
The two diffraction patterns are remarkably
similar.
Section 9.6
79. Electron diffraction demonstrates that moving
matter not only has particle characteristics, but
also wave characteristics
BUT …
The wave nature of matter only becomes of
practical importance with extremely small particles
such as electrons and atoms.
Section 9.6
80. The electron microscope is based on the principle
of matter waves.
This device uses a beam of electrons to view
objects.
Recall that the wavelength of an electron is in the
order of 1 nm, whereas the wavelength of visible
light ranges from 400 – 700 nm
Section 9.6
81. The amount of fuzziness of an image is directly
proportional to the wavelength used to view it
therefore …
the electron microscope is capable of much finer
detail and greater magnification than a
microscope using visible light.
Section 9.6
82. Recall that Bohr chose to analyze the hydrogen
atom, because it is the simplest atom
It is increasingly difficult to analyze atoms with
more that one electron, due to the myriad of
possible electrical interactions
In large atoms, the electrons in the outer orbits are
also partially shielded from the attractive forces of
the nucleus
Section 9.7
83. Although Bohr’s theory was very successful in
explaining the hydrogen atom …
This same theory did not give correct results when
applied to multielectron atoms
Bohr was also unable to explain why the electron
energy levels were quantized
Additionally, Bohr was unable to explain why the
electron did not radiate energy as it traveled in its
orbit
Section 9.7
84. With the discovery of the dual natures of both
waves and particles …
A new kind of physics was developed, called
quantum mechanics or wave mechanics
◦ Developed in the 1920’s and 1930’s as a synthesis of
wave and quantum ideas
Quantum mechanisms also integrated
Heisenberg’s uncertainty principle
◦ The concept of probability replaced the views of
classical mechanics in describing electron movement
Section 9.7
85. In 1926, the Austrian physicist Erwin Schrödinger
presented a new mathematical equation applying
de Broglie’s matter waves.
Schrödinger’s equation was basically a
formulation of the conservation of energy
The simplified form of this equation is …
(Ek + Ep)Ψ = EΨ
◦ Ek, Ep, and E are kinetic, potential, and total energies,
respectively
◦ Ψ = wave function
Section 9.7
86. Schrödinger’s model focuses on the wave nature
of the electron and treats it as a standing wave in
a circular orbit
Permissible orbits must have a circumference that
will accommodate a whole number of electron
wavelengths (λ)
If the circumference will not accommodate a
whole number λ, then this orbit is not ‘probable’
Section 9.7
87. For the electron wave to be stable, the
circumference of the orbit must be a whole
number of wavelengths
Section 9.7
88. Mathematically, the wave function (Ψ ) represents
the wave associated with a particle
For the hydrogen atom it was found that the
equation r2
Ψ 2
represents …
The probability of the hydrogen electron being a
certain distance r from the nucleus
A plot of r2
Ψ 2
versus r for the hydrogen electron
shows that the most probable radius for the
hydrogen electron is r = 0.053nm
◦ Same value as Bohr predicted in 1913!
Section 9.7
90. Although the hydrogen electron may be found at a
radii other than 0.053 nm – the probability is lower
Therefore, when viewed from a probability
standpoint, the “electron cloud” around the
nucleus represents the probability that the
electron will be at that position
The electron cloud is actually a visual
representation of a probability distribution
Section 9.7
91. Although Bohr’s “planetary model” was brilliant
and quite elegant it was not accurate for
multielectron atoms
Schrödinger’s model is highly mathematical and
takes into account the electron’s wave nature
Section 9.7
92. The quantum mechanical model only gives the
location of the electrons in terms of probability
But, this model enables scientists to determine
accurately the energy of the electrons in
multielectron atoms
Knowing the electron’s energy is much more
important than knowing its precise location
Section 9.7
93. E = hf Photon Energy (h= 6.63 x 10-34
Js)
rn = 0.053 n2
nm Hydrogen Electron Orbit Radii
En = (-13.60/n2) eV Hydrogen Electron Energy
Ephoton = Eni – Enf Photon Energy for Transition
λ = h/mv de Broglie Wavelength
Review