This document provides an overview of a presentation on atomic structure from a chemistry textbook. It includes sections on the development of the atomic model, the quantum model of the atom, and electron configurations. It describes objectives for each section and provides content on topics like the photoelectric effect, line emission spectra, Bohr's model of the hydrogen atom, quantum numbers, and more. Navigation instructions are also provided at the beginning for accessing the different parts of the presentation.
Light is electromagnetic radiation that allows for vision. It is produced by the sun and bounces off objects into our eyes, enabling sight. Light exhibits properties of both waves and particles. As a wave, light displays phenomena like reflection, refraction, interference and diffraction. Reflection causes light to bounce off surfaces, while refraction bends light when it passes from one medium to another. Interference and diffraction are results of light behaving as a wave. The photoelectric effect provided evidence that light also behaves as a particle. Polarization demonstrated that light waves oscillate transversely. Polarizing filters allow only certain transverse oscillations to pass through. Malus's law describes how light intensity is reduced when passing through multiple polarizing filters based on
Light is electromagnetic radiation that exhibits properties of both waves and particles. It travels as transverse electromagnetic waves at a speed of approximately 300,000 km/s in a vacuum. When light interacts with matter, it can be reflected, refracted, dispersed, absorbed, or cause materials to become polarized. Key phenomena include reflection at interfaces, refraction due to changes in refractive index, dispersion causing separation of wavelengths, selective absorption of different colors, and polarization of light through restricting vibrations to one plane.
The document discusses several topics related to atomic structure and quantum mechanics. It begins by discussing quantization and how the work of Planck, Einstein, and others led to the concept of photons and quantized energy levels in atoms. It then discusses the photoelectric effect demonstrated by Einstein that helped establish the particle nature of light. Finally, it discusses population inversion in lasers and how certain materials like argon can be excited to a state that allows for stimulated emission of coherent light.
The document discusses various properties of light including its nature as both a wave and particle, how it reflects, refracts, and interacts through interference and polarization. It covers key experiments such as Young's double slit experiment that demonstrated light's wavelike properties and the photoelectric effect that showed its particulate nature. The properties of reflection, refraction, dispersion, interference, diffraction, polarization and Brewster's law are also defined and explained in the context of light as an electromagnetic wave.
Light is electromagnetic radiation visible to the human eye that has wavelengths between 380-740 nm. It exhibits properties of both waves and particles. Light travels at 299,792,458 m/s in a vacuum. It can be produced through various mechanisms and sources like the sun. Theories of light include the particle theory, wave theory, and quantum theory. Light behaves as both a wave and particle and can be reflected, exhibiting the laws of reflection.
The document discusses the nature of light, including its behavior as both a particle and wave. It covers various topics such as the sources of light, properties of light like reflection, refraction, dispersion, and evidence that supports both wave and particle theories of light such as the photoelectric effect and double-slit experiment. The key point is that light has a dual nature, exhibiting both wave-like properties and particle-like properties, which was a challenging concept to reconcile historically.
This presentation introduces the characteristics of light and the electromagnetic spectrum. It discusses the different types of electromagnetic waves including their frequencies and wavelengths. It describes the parts of a wave like amplitude, frequency, period, and wavelength. It explains that light travels at a finite speed of 299,792,458 meters per second. It also covers how the brightness of light decreases with the inverse square of the distance from the source.
This document summarizes Isaac Newton's particle theory of light from the 17th century. [1] Newton proposed that light consisted of small particles called corpuscles that traveled in straight lines. [2] The particle theory explained observations of reflection, shadows, and light traveling in straight paths. [3] However, the particle theory struggled to explain phenomena like diffraction and interference that are characteristic of waves.
Light is electromagnetic radiation that allows for vision. It is produced by the sun and bounces off objects into our eyes, enabling sight. Light exhibits properties of both waves and particles. As a wave, light displays phenomena like reflection, refraction, interference and diffraction. Reflection causes light to bounce off surfaces, while refraction bends light when it passes from one medium to another. Interference and diffraction are results of light behaving as a wave. The photoelectric effect provided evidence that light also behaves as a particle. Polarization demonstrated that light waves oscillate transversely. Polarizing filters allow only certain transverse oscillations to pass through. Malus's law describes how light intensity is reduced when passing through multiple polarizing filters based on
Light is electromagnetic radiation that exhibits properties of both waves and particles. It travels as transverse electromagnetic waves at a speed of approximately 300,000 km/s in a vacuum. When light interacts with matter, it can be reflected, refracted, dispersed, absorbed, or cause materials to become polarized. Key phenomena include reflection at interfaces, refraction due to changes in refractive index, dispersion causing separation of wavelengths, selective absorption of different colors, and polarization of light through restricting vibrations to one plane.
The document discusses several topics related to atomic structure and quantum mechanics. It begins by discussing quantization and how the work of Planck, Einstein, and others led to the concept of photons and quantized energy levels in atoms. It then discusses the photoelectric effect demonstrated by Einstein that helped establish the particle nature of light. Finally, it discusses population inversion in lasers and how certain materials like argon can be excited to a state that allows for stimulated emission of coherent light.
The document discusses various properties of light including its nature as both a wave and particle, how it reflects, refracts, and interacts through interference and polarization. It covers key experiments such as Young's double slit experiment that demonstrated light's wavelike properties and the photoelectric effect that showed its particulate nature. The properties of reflection, refraction, dispersion, interference, diffraction, polarization and Brewster's law are also defined and explained in the context of light as an electromagnetic wave.
Light is electromagnetic radiation visible to the human eye that has wavelengths between 380-740 nm. It exhibits properties of both waves and particles. Light travels at 299,792,458 m/s in a vacuum. It can be produced through various mechanisms and sources like the sun. Theories of light include the particle theory, wave theory, and quantum theory. Light behaves as both a wave and particle and can be reflected, exhibiting the laws of reflection.
The document discusses the nature of light, including its behavior as both a particle and wave. It covers various topics such as the sources of light, properties of light like reflection, refraction, dispersion, and evidence that supports both wave and particle theories of light such as the photoelectric effect and double-slit experiment. The key point is that light has a dual nature, exhibiting both wave-like properties and particle-like properties, which was a challenging concept to reconcile historically.
This presentation introduces the characteristics of light and the electromagnetic spectrum. It discusses the different types of electromagnetic waves including their frequencies and wavelengths. It describes the parts of a wave like amplitude, frequency, period, and wavelength. It explains that light travels at a finite speed of 299,792,458 meters per second. It also covers how the brightness of light decreases with the inverse square of the distance from the source.
This document summarizes Isaac Newton's particle theory of light from the 17th century. [1] Newton proposed that light consisted of small particles called corpuscles that traveled in straight lines. [2] The particle theory explained observations of reflection, shadows, and light traveling in straight paths. [3] However, the particle theory struggled to explain phenomena like diffraction and interference that are characteristic of waves.
This document discusses various properties of light, including its behavior as both particles (photons) and waves. It describes experiments by Newton showing visible light can be separated into different colors/wavelengths. It also discusses how different wavelengths of electromagnetic radiation can penetrate the atmosphere, allowing astronomers to study celestial objects across the electromagnetic spectrum. Finally, it summarizes laws like the Stefan-Boltzmann and Wien's laws that describe how the radiation of a blackbody relates to its temperature.
MRI relies on the spin properties of hydrogen nuclei in the body. When placed in a strong magnetic field, hydrogen nuclei align with the field and precess at their Larmor frequency. Applying a radiofrequency pulse at the Larmor frequency causes the nuclei to resonate and flip their alignment, inducing a voltage in a receiver coil that is detected as the MR signal. The signal decays over time as the nuclei relax back to their original alignment, with their T1 and T2 relaxation times characterizing the recovery of longitudinal magnetization and decay of transverse magnetization respectively. Pulse sequences are defined by repetition time TR and echo time TE to control T1 and T2 contrast in the resulting images.
POLARIZATION OF LIGHT - BIREFRINGENCE AND HUYGEN'S THEORY OF DOUBLE REFRACTIONAnuroop Ashok
Huygen's theory of double refraction explains the phenomenon of birefringence in crystals like calcite. According to the theory:
- Each point in a birefringent crystal produces two types of wavefronts - a spherical wavefront for the ordinary ray and an ellipsoidal wavefront for the extraordinary ray.
- The shape of the wavefronts depends on whether the crystal is negative or positive. In negative crystals like calcite, the extraordinary wavefront is outside the ordinary wavefront, while in positive crystals it is inside.
- Huygen's principle treats each point on a wavefront as a secondary source of spherical wavelets, and the envelope of these wavelets makes up the
Light is a form of energy that can be emitted or reflected and travels in straight paths. There are several sources of light including incandescence from heat, phosphorescence through slow energy release, and fluorescence or chemiluminescence from chemical reactions. Objects can be transparent and allow full light transmission, translucent to partially transmit light, or opaque to block all light. The visible light spectrum ranges from red to violet wavelengths, and color is determined by which wavelengths of light are reflected or absorbed. Light acts as a wave that transfers energy through amplitude and wavelength.
IB Chemistry on Nuclear Magnetic Resonance, Chemical Shift and Splitting PatternLawrence kok
This document discusses various analytical techniques used in chemistry, including both classical and instrumental methods. Classical methods involve qualitative and quantitative analysis using chemical tests, titrations, and gravimetric analysis. Instrumental methods discussed include various types of spectroscopy such as infrared spectroscopy, nuclear magnetic resonance spectroscopy, and chromatography techniques used for separation analysis. The document provides details on the principles, applications, and information provided by different analytical techniques.
This document provides an overview of key concepts in geometric optics, including:
- Light exhibits both wave and particle properties, with different experiments supporting each model.
- Ray optics approximates light propagation using straight line paths. Reflection and refraction cause changes in light's direction at material boundaries.
- The law of reflection states that the angle of incidence equals the angle of reflection. Refraction is governed by Snell's law.
- Total internal reflection occurs when light passes from a high to low refractive index material beyond the critical angle, and is used in applications like fiber optics.
Huygen's principle describes how each point on a wavefront acts as a secondary source of waves, and that the new wavefront is the envelope of these secondary waves. It provides a method for determining the propagation and behavior of light waves. The principle is based on assuming each point on the initial wavefront emits spherical wavelets, and the new wavefront is the envelope of these secondary waves. It can be used to understand phenomena like interference and diffraction of light.
Polarization refers to the orientation of oscillations in a transverse wave such as light. This document discusses several types of polarization including linear, circular, and elliptical polarization. It also describes how polarization occurs through reflection, scattering, and the use of polarizers. Polarization can be quantified using equations that describe the electric field orientation over time, with special cases corresponding to linear, circular, and elliptical polarization.
1. In the 17th century, Isaac Newton and Christian Huygens proposed different theories on the nature of light - Newton believed light consisted of particles while Huygens believed it was a wave.
2. Through experiments like the double slit experiment, it was shown that light exhibits both wave-like and particle-like properties.
3. Modern understanding is that light has a dual nature, it can behave as a particle called a photon as well as a wave. This is called the wave-particle duality of light.
This document discusses the nature of light. It begins by asking questions about whether light is a wave or particle and how it is produced and travels. It then provides information about light, such as its speed, ability to carry energy and information, and travel in straight lines. The document explains that light is both a wave and particle, with photons as the particle. It discusses the electromagnetic spectrum and how light waves carry energy related to their wavelength. Light is produced through electron excitation in atoms. The full spectrum is described, from radio to gamma rays.
The document provides background information on masers (microwave amplification by stimulated emission of radiation). It discusses how masers were first conceptualized in the 1950s and the development of the first ammonia maser in 1953. Masers operate using the principle of stimulated emission and population inversion to amplify microwave radiation. Various types of astrophysical masers have been discovered in space which can be used to study astronomical environments.
This document provides instructions and content for a slideshow presentation on atoms and the structure of the atom. It includes 5 sections: How to Use This Presentation, Resources/Chapter Menu, Table of Contents, Section 1 on the historical development of atomic theory, and Section 2 on the structure of the atom. The presentation defines key terms like isotope, atomic number, and mass number. It also summarizes experiments that discovered subatomic particles like the electron and atomic nucleus.
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.
Electrons are important because their arrangement in atomic orbitals determines an element's properties and reactions. Electrons exhibit both wave-like and particle-like behavior. According to quantum theory, electrons occupy specific atomic orbitals and energy levels. Their configuration is defined by rules like the Aufbau principle and Pauli exclusion principle. Valence electrons in the outermost shell determine an element's chemical behavior.
This document provides instructions for navigating an interactive presentation on forces and motion from a physics textbook. It outlines how to view the presentation as a slideshow, advance through slides, access different chapters and lessons, and exit the slideshow. The presentation contains chapters on topics like Newton's laws of motion, forces, force diagrams, and examples with objectives and step-by-step solutions. Users can access additional resources like transparencies, test prep, visual concepts and sample problems through the slides.
The document is a chapter from a physics textbook about light and reflection. It discusses the electromagnetic spectrum and describes how light is a form of electromagnetic radiation. It also explains the law of reflection for flat mirrors, how mirrors form virtual images, and concepts of polarization of light waves.
Electrons in Atoms can be summarized as follows:
1) Light exhibits both wave-like and particle-like properties, with electrons in atoms also displaying wave-like characteristics that help explain atomic structure.
2) Atoms are arranged according to a set of rules, with electrons occupying specific energy levels and orbitals around the nucleus according to the aufbau principle and other quantum rules.
3) The Bohr and quantum mechanical models both describe the discrete energy levels electrons can occupy in atoms, with the latter treating electrons as waves rather than fixed orbits and establishing probability distributions rather than precise paths.
This document discusses radioactivity and nuclear chemistry. It begins by explaining how nuclear medicine uses changes in nuclear structure for diagnostic and therapeutic purposes. It then summarizes the discoveries of radioactivity by Becquerel, the Curies, and Rutherford. Specifically, it describes how Becquerel discovered that uranium minerals emitted radiation without an external energy source, how the Curies isolated radioactive elements like radium and polonium, and how Rutherford discovered the three main types of radioactive decay and used them to determine nuclear structure. The document also provides explanations of key nuclear processes like alpha, beta, gamma, positron emission and electron capture.
This document provides an overview of nuclear chemistry concepts including nuclear radiation, radioactive decay, and nuclear reactions. Section 24.1 discusses the discovery of radiation and defines types of nuclear radiation such as alpha, beta, and gamma rays. Section 24.2 explains radioactive decay and half-lives. It also describes methods of radioactive dating. Section 24.3 covers nuclear reactions including nuclear fission, fusion, and how nuclear reactors generate electricity through controlled fission.
1. The document discusses the history and development of lasers, beginning with Einstein's 1917 prediction of stimulated emission which laid the foundation for laser technology.
2. It describes the key components of lasers - the active medium which provides energy levels, pumping to create population inversion between levels, and an optical cavity to amplify stimulated emission.
3. Examples of specific lasers are discussed in more detail, including Nd:YAG, carbon dioxide, and semiconductor lasers, outlining their construction, working principles, and applications in fields such as communication, computing, industry, medicine, and more.
This document discusses various properties of light, including its behavior as both particles (photons) and waves. It describes experiments by Newton showing visible light can be separated into different colors/wavelengths. It also discusses how different wavelengths of electromagnetic radiation can penetrate the atmosphere, allowing astronomers to study celestial objects across the electromagnetic spectrum. Finally, it summarizes laws like the Stefan-Boltzmann and Wien's laws that describe how the radiation of a blackbody relates to its temperature.
MRI relies on the spin properties of hydrogen nuclei in the body. When placed in a strong magnetic field, hydrogen nuclei align with the field and precess at their Larmor frequency. Applying a radiofrequency pulse at the Larmor frequency causes the nuclei to resonate and flip their alignment, inducing a voltage in a receiver coil that is detected as the MR signal. The signal decays over time as the nuclei relax back to their original alignment, with their T1 and T2 relaxation times characterizing the recovery of longitudinal magnetization and decay of transverse magnetization respectively. Pulse sequences are defined by repetition time TR and echo time TE to control T1 and T2 contrast in the resulting images.
POLARIZATION OF LIGHT - BIREFRINGENCE AND HUYGEN'S THEORY OF DOUBLE REFRACTIONAnuroop Ashok
Huygen's theory of double refraction explains the phenomenon of birefringence in crystals like calcite. According to the theory:
- Each point in a birefringent crystal produces two types of wavefronts - a spherical wavefront for the ordinary ray and an ellipsoidal wavefront for the extraordinary ray.
- The shape of the wavefronts depends on whether the crystal is negative or positive. In negative crystals like calcite, the extraordinary wavefront is outside the ordinary wavefront, while in positive crystals it is inside.
- Huygen's principle treats each point on a wavefront as a secondary source of spherical wavelets, and the envelope of these wavelets makes up the
Light is a form of energy that can be emitted or reflected and travels in straight paths. There are several sources of light including incandescence from heat, phosphorescence through slow energy release, and fluorescence or chemiluminescence from chemical reactions. Objects can be transparent and allow full light transmission, translucent to partially transmit light, or opaque to block all light. The visible light spectrum ranges from red to violet wavelengths, and color is determined by which wavelengths of light are reflected or absorbed. Light acts as a wave that transfers energy through amplitude and wavelength.
IB Chemistry on Nuclear Magnetic Resonance, Chemical Shift and Splitting PatternLawrence kok
This document discusses various analytical techniques used in chemistry, including both classical and instrumental methods. Classical methods involve qualitative and quantitative analysis using chemical tests, titrations, and gravimetric analysis. Instrumental methods discussed include various types of spectroscopy such as infrared spectroscopy, nuclear magnetic resonance spectroscopy, and chromatography techniques used for separation analysis. The document provides details on the principles, applications, and information provided by different analytical techniques.
This document provides an overview of key concepts in geometric optics, including:
- Light exhibits both wave and particle properties, with different experiments supporting each model.
- Ray optics approximates light propagation using straight line paths. Reflection and refraction cause changes in light's direction at material boundaries.
- The law of reflection states that the angle of incidence equals the angle of reflection. Refraction is governed by Snell's law.
- Total internal reflection occurs when light passes from a high to low refractive index material beyond the critical angle, and is used in applications like fiber optics.
Huygen's principle describes how each point on a wavefront acts as a secondary source of waves, and that the new wavefront is the envelope of these secondary waves. It provides a method for determining the propagation and behavior of light waves. The principle is based on assuming each point on the initial wavefront emits spherical wavelets, and the new wavefront is the envelope of these secondary waves. It can be used to understand phenomena like interference and diffraction of light.
Polarization refers to the orientation of oscillations in a transverse wave such as light. This document discusses several types of polarization including linear, circular, and elliptical polarization. It also describes how polarization occurs through reflection, scattering, and the use of polarizers. Polarization can be quantified using equations that describe the electric field orientation over time, with special cases corresponding to linear, circular, and elliptical polarization.
1. In the 17th century, Isaac Newton and Christian Huygens proposed different theories on the nature of light - Newton believed light consisted of particles while Huygens believed it was a wave.
2. Through experiments like the double slit experiment, it was shown that light exhibits both wave-like and particle-like properties.
3. Modern understanding is that light has a dual nature, it can behave as a particle called a photon as well as a wave. This is called the wave-particle duality of light.
This document discusses the nature of light. It begins by asking questions about whether light is a wave or particle and how it is produced and travels. It then provides information about light, such as its speed, ability to carry energy and information, and travel in straight lines. The document explains that light is both a wave and particle, with photons as the particle. It discusses the electromagnetic spectrum and how light waves carry energy related to their wavelength. Light is produced through electron excitation in atoms. The full spectrum is described, from radio to gamma rays.
The document provides background information on masers (microwave amplification by stimulated emission of radiation). It discusses how masers were first conceptualized in the 1950s and the development of the first ammonia maser in 1953. Masers operate using the principle of stimulated emission and population inversion to amplify microwave radiation. Various types of astrophysical masers have been discovered in space which can be used to study astronomical environments.
This document provides instructions and content for a slideshow presentation on atoms and the structure of the atom. It includes 5 sections: How to Use This Presentation, Resources/Chapter Menu, Table of Contents, Section 1 on the historical development of atomic theory, and Section 2 on the structure of the atom. The presentation defines key terms like isotope, atomic number, and mass number. It also summarizes experiments that discovered subatomic particles like the electron and atomic nucleus.
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.
Electrons are important because their arrangement in atomic orbitals determines an element's properties and reactions. Electrons exhibit both wave-like and particle-like behavior. According to quantum theory, electrons occupy specific atomic orbitals and energy levels. Their configuration is defined by rules like the Aufbau principle and Pauli exclusion principle. Valence electrons in the outermost shell determine an element's chemical behavior.
This document provides instructions for navigating an interactive presentation on forces and motion from a physics textbook. It outlines how to view the presentation as a slideshow, advance through slides, access different chapters and lessons, and exit the slideshow. The presentation contains chapters on topics like Newton's laws of motion, forces, force diagrams, and examples with objectives and step-by-step solutions. Users can access additional resources like transparencies, test prep, visual concepts and sample problems through the slides.
The document is a chapter from a physics textbook about light and reflection. It discusses the electromagnetic spectrum and describes how light is a form of electromagnetic radiation. It also explains the law of reflection for flat mirrors, how mirrors form virtual images, and concepts of polarization of light waves.
Electrons in Atoms can be summarized as follows:
1) Light exhibits both wave-like and particle-like properties, with electrons in atoms also displaying wave-like characteristics that help explain atomic structure.
2) Atoms are arranged according to a set of rules, with electrons occupying specific energy levels and orbitals around the nucleus according to the aufbau principle and other quantum rules.
3) The Bohr and quantum mechanical models both describe the discrete energy levels electrons can occupy in atoms, with the latter treating electrons as waves rather than fixed orbits and establishing probability distributions rather than precise paths.
This document discusses radioactivity and nuclear chemistry. It begins by explaining how nuclear medicine uses changes in nuclear structure for diagnostic and therapeutic purposes. It then summarizes the discoveries of radioactivity by Becquerel, the Curies, and Rutherford. Specifically, it describes how Becquerel discovered that uranium minerals emitted radiation without an external energy source, how the Curies isolated radioactive elements like radium and polonium, and how Rutherford discovered the three main types of radioactive decay and used them to determine nuclear structure. The document also provides explanations of key nuclear processes like alpha, beta, gamma, positron emission and electron capture.
This document provides an overview of nuclear chemistry concepts including nuclear radiation, radioactive decay, and nuclear reactions. Section 24.1 discusses the discovery of radiation and defines types of nuclear radiation such as alpha, beta, and gamma rays. Section 24.2 explains radioactive decay and half-lives. It also describes methods of radioactive dating. Section 24.3 covers nuclear reactions including nuclear fission, fusion, and how nuclear reactors generate electricity through controlled fission.
1. The document discusses the history and development of lasers, beginning with Einstein's 1917 prediction of stimulated emission which laid the foundation for laser technology.
2. It describes the key components of lasers - the active medium which provides energy levels, pumping to create population inversion between levels, and an optical cavity to amplify stimulated emission.
3. Examples of specific lasers are discussed in more detail, including Nd:YAG, carbon dioxide, and semiconductor lasers, outlining their construction, working principles, and applications in fields such as communication, computing, industry, medicine, and more.
The Bohr model of the atom consists of a dense
positive nucleus surrounded by electrons in
shells. The nucleus contains nucleons which
are either protons or neutrons. The proton has
a positive charge and an atomic mass of 1 AMU.
The neutron has zero charge and an atomic
mass of 1 AMU. The atomic number (Z) is
equal to the number of protons in the nucleus.
The atomic mass (A) is equal to the sum of the
neutrons and protons in the nucleus. The electron has a negative charge and a mass of almost
zero. Electrons in an atom only move in specifi c orbits. Each orbit or shell has its own binding energy. The binding energy is the energy
required to remove an electron from its shell.
The shells closer to the nucleus have higher
binding energies. Ionization occurs when an
electron is removed from an atom. This results
in an ion pair made up of one positive and
one negative ion. Ionizing radiation consists
of electromagnetic and particulate radiations
with enough energy to ionize atoms. X-rays
and gamma rays are forms of electromagnetic
radiation. Alpha and beta radiations are forms of
particulate radiation.
There are two systems of radiation units, the
SI and the conventional. The units of exposure
are the roentgen (R) and the coulombs per
kilogram (C/kg). The units of dose are the gray
and the rad. The units of the effective dose are
the sievert and the rem.
Elements with similar electron shell structures have similar chemical properties. Isotopes
are elements with the same atomic number but
different atomic masses. Isotopes have the same
chemical properties. The atomic weight of an
element is the average of the atomic masses of
naturally occurring isotopes. When elements
are arranged in order of increasing atomic number, they form the periodic table of elements.
Beyond bohr de broglie and heisenberg for universe to atom module cfiCraig Fitzsimmons
This document summarizes the development of quantum mechanics from Bohr's early model of the atom to the fully quantum models developed in the 1920s. It discusses modifications made to Bohr's model, such as elliptical orbits and additional quantum numbers. Key figures who contributed include de Broglie, Heisenberg, Schrodinger, and Pauli. De Broglie hypothesized that particles have wave-like properties, which was confirmed by Davisson and Germer's electron diffraction experiment. Heisenberg formulated matrix mechanics and proposed the uncertainty principle. Schrodinger developed wave mechanics using wave functions, and his equation can be used to calculate energy levels.
The document discusses the structure of atoms and their components. It begins by outlining John Dalton's atomic theory from 1803. It then defines key atomic particles like protons, neutrons, and electrons, and describes their relative charges and masses. The document outlines the Bohr and quantum mechanical models of atomic structure. It discusses how electrons can exist only in discrete energy levels defined by principal and angular momentum quantum numbers. This quantization explains atoms' distinct emission spectra and periodic trends.
Electrons are important because their wavelike properties help explain atomic structure and spectra. Electrons can only gain or lose energy in specific quantized amounts called quanta. The quantum mechanical model treats electrons as waves and uses probability maps instead of fixed orbits, with electrons located in regions called atomic orbitals based on their quantum numbers.
- The document discusses the history and structure of atoms. It explains that atoms are the smallest particle into which elements can be divided while still maintaining their chemical properties. Atoms consist of protons, neutrons, and electrons. Protons and neutrons are located in the dense nucleus at the center, while electrons move around the nucleus. The number of protons determines the element, while the number of neutrons can vary between isotopes of the same element.
General terms in nuclear safety and security sphere. nuclear fuel cycle (nfc)...Katerina Sviridova
This document provides information about nuclear physics terms and concepts. It defines key terms like half-life, nuclei, binding energy, neutron, isotope, and absorption. It also outlines the major periods and discoveries in the history of nuclear physics from 1868 to the present. Some key events mentioned include the discovery of radioactivity, x-rays, the electron, nuclear fission, and theories of quantum mechanics and nuclear reactions. The document also provides examples of using the concept of half-life to model radioactive decay over time.
This document provides an overview of radioactivity and its medical uses. It discusses the structure of atoms and their components, isotopes, radioactivity, nuclear equations, radiation units, half-lives, and medical applications of radioisotopes. Specifically, it explains how radioisotopes can be used for diagnostic imaging and cancer treatment by concentrating in certain tissues and emitting detectable radiation. Radioisotopes with short half-lives are preferred for medical use so that radioactivity is eliminated from the body quickly.
The document discusses the history of discoveries related to atomic structure. Key developments include:
- Dalton's atomic theory from 1808 which proposed that matter is made of indivisible atoms.
- J.J. Thomson's discovery of electrons in cathode rays in 1897, proving atoms have internal structure.
- Ernest Rutherford's gold foil experiment in 1911 which showed that atoms have a small, dense nucleus.
- Niels Bohr incorporated Planck's quantum theory into his 1913 model of the atom, explaining atomic spectra.
- Later discoveries refined atomic models, including Heisenberg's uncertainty principle, Schrodinger's wave mechanical model, and the introduction of quantum numbers to describe electron configurations
This document provides an overview of Module 4 which covers Quantum Mechanics and LASERs. The key topics in Quantum Mechanics include Planck's Law, wave-particle duality, de Broglie's hypothesis, Heisenberg's Uncertainty Principle, Schrodinger's wave equation, and wave functions. LASER is also introduced including spontaneous and stimulated emission, laser construction and working principles of CO2 and semiconductor lasers, and applications such as laser range finders and data storage. References for 15 books on related topics are provided.
This document discusses the development of atomic theory from ancient Greek philosophers to the modern quantum mechanical model. Key contributors and discoveries include Dalton formulating the first atomic theory, Thomson discovering the electron, Rutherford deducing the nuclear atom from alpha particle scattering experiments, and Bohr, de Broglie, Schrodinger, and others developing quantum mechanics to explain atomic structure and spectra. The modern atomic model consists of electrons in quantized energy levels around an atomic nucleus composed of protons and neutrons, which is summarized by the periodic table and determines chemical properties.
PPT on Alternate Wetting and Drying presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
(June 12, 2024) Webinar: Development of PET theranostics targeting the molecu...Scintica Instrumentation
Targeting Hsp90 and its pathogen Orthologs with Tethered Inhibitors as a Diagnostic and Therapeutic Strategy for cancer and infectious diseases with Dr. Timothy Haystead.
Microbial interaction
Microorganisms interacts with each other and can be physically associated with another organisms in a variety of ways.
One organism can be located on the surface of another organism as an ectobiont or located within another organism as endobiont.
Microbial interaction may be positive such as mutualism, proto-cooperation, commensalism or may be negative such as parasitism, predation or competition
Types of microbial interaction
Positive interaction: mutualism, proto-cooperation, commensalism
Negative interaction: Ammensalism (antagonism), parasitism, predation, competition
I. Mutualism:
It is defined as the relationship in which each organism in interaction gets benefits from association. It is an obligatory relationship in which mutualist and host are metabolically dependent on each other.
Mutualistic relationship is very specific where one member of association cannot be replaced by another species.
Mutualism require close physical contact between interacting organisms.
Relationship of mutualism allows organisms to exist in habitat that could not occupied by either species alone.
Mutualistic relationship between organisms allows them to act as a single organism.
Examples of mutualism:
i. Lichens:
Lichens are excellent example of mutualism.
They are the association of specific fungi and certain genus of algae. In lichen, fungal partner is called mycobiont and algal partner is called
II. Syntrophism:
It is an association in which the growth of one organism either depends on or improved by the substrate provided by another organism.
In syntrophism both organism in association gets benefits.
Compound A
Utilized by population 1
Compound B
Utilized by population 2
Compound C
utilized by both Population 1+2
Products
In this theoretical example of syntrophism, population 1 is able to utilize and metabolize compound A, forming compound B but cannot metabolize beyond compound B without co-operation of population 2. Population 2is unable to utilize compound A but it can metabolize compound B forming compound C. Then both population 1 and 2 are able to carry out metabolic reaction which leads to formation of end product that neither population could produce alone.
Examples of syntrophism:
i. Methanogenic ecosystem in sludge digester
Methane produced by methanogenic bacteria depends upon interspecies hydrogen transfer by other fermentative bacteria.
Anaerobic fermentative bacteria generate CO2 and H2 utilizing carbohydrates which is then utilized by methanogenic bacteria (Methanobacter) to produce methane.
ii. Lactobacillus arobinosus and Enterococcus faecalis:
In the minimal media, Lactobacillus arobinosus and Enterococcus faecalis are able to grow together but not alone.
The synergistic relationship between E. faecalis and L. arobinosus occurs in which E. faecalis require folic acid
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
CLASS 12th CHEMISTRY SOLID STATE ppt (Animated)eitps1506
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Dive into the fascinating realm of solid-state physics with our meticulously crafted online PowerPoint presentation. This immersive educational resource offers a comprehensive exploration of the fundamental concepts, theories, and applications within the realm of solid-state physics.
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With visually engaging slides, informative content, and interactive elements, our online PowerPoint presentation serves as a valuable resource for students, educators, and enthusiasts alike, facilitating a deeper understanding of the captivating world of solid-state physics. Explore the intricacies of solid-state materials and unlock the secrets behind their remarkable properties with our comprehensive presentation.
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...Sérgio Sacani
Context. The observation of several L-band emission sources in the S cluster has led to a rich discussion of their nature. However, a definitive answer to the classification of the dusty objects requires an explanation for the detection of compact Doppler-shifted Brγ emission. The ionized hydrogen in combination with the observation of mid-infrared L-band continuum emission suggests that most of these sources are embedded in a dusty envelope. These embedded sources are part of the S-cluster, and their relationship to the S-stars is still under debate. To date, the question of the origin of these two populations has been vague, although all explanations favor migration processes for the individual cluster members. Aims. This work revisits the S-cluster and its dusty members orbiting the supermassive black hole SgrA* on bound Keplerian orbits from a kinematic perspective. The aim is to explore the Keplerian parameters for patterns that might imply a nonrandom distribution of the sample. Additionally, various analytical aspects are considered to address the nature of the dusty sources. Methods. Based on the photometric analysis, we estimated the individual H−K and K−L colors for the source sample and compared the results to known cluster members. The classification revealed a noticeable contrast between the S-stars and the dusty sources. To fit the flux-density distribution, we utilized the radiative transfer code HYPERION and implemented a young stellar object Class I model. We obtained the position angle from the Keplerian fit results; additionally, we analyzed the distribution of the inclinations and the longitudes of the ascending node. Results. The colors of the dusty sources suggest a stellar nature consistent with the spectral energy distribution in the near and midinfrared domains. Furthermore, the evaporation timescales of dusty and gaseous clumps in the vicinity of SgrA* are much shorter ( 2yr) than the epochs covered by the observations (≈15yr). In addition to the strong evidence for the stellar classification of the D-sources, we also find a clear disk-like pattern following the arrangements of S-stars proposed in the literature. Furthermore, we find a global intrinsic inclination for all dusty sources of 60 ± 20◦, implying a common formation process. Conclusions. The pattern of the dusty sources manifested in the distribution of the position angles, inclinations, and longitudes of the ascending node strongly suggests two different scenarios: the main-sequence stars and the dusty stellar S-cluster sources share a common formation history or migrated with a similar formation channel in the vicinity of SgrA*. Alternatively, the gravitational influence of SgrA* in combination with a massive perturber, such as a putative intermediate mass black hole in the IRS 13 cluster, forces the dusty objects and S-stars to follow a particular orbital arrangement. Key words. stars: black holes– stars: formation– Galaxy: center– galaxies: star formation
Sexuality - Issues, Attitude and Behaviour - Applied Social Psychology - Psyc...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
The cost of acquiring information by natural selectionCarl Bergstrom
This is a short talk that I gave at the Banff International Research Station workshop on Modeling and Theory in Population Biology. The idea is to try to understand how the burden of natural selection relates to the amount of information that selection puts into the genome.
It's based on the first part of this research paper:
The cost of information acquisition by natural selection
Ryan Seamus McGee, Olivia Kosterlitz, Artem Kaznatcheev, Benjamin Kerr, Carl T. Bergstrom
bioRxiv 2022.07.02.498577; doi: https://doi.org/10.1101/2022.07.02.498577
Mending Clothing to Support Sustainable Fashion_CIMaR 2024.pdfSelcen Ozturkcan
Ozturkcan, S., Berndt, A., & Angelakis, A. (2024). Mending clothing to support sustainable fashion. Presented at the 31st Annual Conference by the Consortium for International Marketing Research (CIMaR), 10-13 Jun 2024, University of Gävle, Sweden.
PPT on Direct Seeded Rice presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.