The document summarizes the development of atomic models from Rutherford to the current quantum mechanical model. It discusses inadequacies in Rutherford's model that could not explain atomic properties and emissions. Bohr proposed electrons orbit in distinct energy levels, but this failed to explain multi-electron atoms. The quantum mechanical model treats electrons as waves using Schrodinger's equation, describing electrons as probability distributions rather than particles. It introduces quantum numbers to characterize electron states and explains how orbitals are filled according to various rules.
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.
This lesson will help you know how atoms of each element are arranged in an orbital and where atoms are exactly located that give distinct characteristics to the element.
This presentation is about the ionisation of energy of hydrogen, way to compute the value of ionisation energy of hydrogen, quantum numbers and a brief description of Schrodinger Equation.
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.
This lesson will help you know how atoms of each element are arranged in an orbital and where atoms are exactly located that give distinct characteristics to the element.
This presentation is about the ionisation of energy of hydrogen, way to compute the value of ionisation energy of hydrogen, quantum numbers and a brief description of Schrodinger Equation.
Quantum Numbers and Atomic Orbitals By solving t.pdfarasanlethers
Quantum Numbers and Atomic Orbitals By solving the Schrödinger equation (Hy
= Ey), we obtain a set of mathematical equations, called wave functions (y), which describe the
probability of finding electrons at certain energy levels within an atom. A wave function for an
electron in an atom is called an atomic orbital; this atomic orbital describes a region of space in
which there is a high probability of finding the electron. Energy changes within an atom are the
result of an electron changing from a wave pattern with one energy to a wave pattern with a
different energy (usually accompanied by the absorption or emission of a photon of light). Each
electron in an atom is described by four different quantum numbers. The first three (n, l, ml)
specify the particular orbital of interest, and the fourth (ms) specifies how many electrons can
occupy that orbital. Principal Quantum Number (n): n = 1, 2, 3, …, 8 Specifies the energy of
an electron and the size of the orbital (the distance from the nucleus of the peak in a radial
probability distribution plot). All orbitals that have the same value of n are said to be in the same
shell (level). For a hydrogen atom with n=1, the electron is in its ground state; if the electron is in
the n=2 orbital, it is in an excited state. The total number of orbitals for a given n value is n2.
Angular Momentum (Secondary, Azimunthal) Quantum Number (l): l = 0, ..., n-1. Specifies the
shape of an orbital with a particular principal quantum number. The secondary quantum number
divides the shells into smaller groups of orbitals called subshells (sublevels). Usually, a letter
code is used to identify l to avoid confusion with n: l 0 1 2 3 4 5 ... Letter s p d f g h ... The
subshell with n=2 and l=1 is the 2p subshell; if n=3 and l=0, it is the 3s subshell, and so on. The
value of l also has a slight effect on the energy of the subshell; the energy of the subshell
increases with l (s < p < d < f). Magnetic Quantum Number (ml): ml = -l, ..., 0, ..., +l. Specifies
the orientation in space of an orbital of a given energy (n) and shape (l). This number divides the
subshell into individual orbitals which hold the electrons; there are 2l+1 orbitals in each subshell.
Thus the s subshell has only one orbital, the p subshell has three orbitals, and so on. Spin
Quantum Number (ms): ms = +½ or -½. Specifies the orientation of the spin axis of an electron.
An electron can spin in only one of two directions (sometimes called up and down). The Pauli
exclusion principle (Wolfgang Pauli, Nobel Prize 1945) states that no two electrons in the same
atom can have identical values for all four of their quantum numbers. What this means is that no
more than two electrons can occupy the same orbital, and that two electrons in the same orbital
must have opposite spins. Because an electron spins, it creates a magnetic field, which can be
oriented in one of two directions. For two electrons in the same orbital, the spins must be
opposite to each oth.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
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Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Safalta Digital marketing institute in Noida, provide complete applications that encompass a huge range of virtual advertising and marketing additives, which includes search engine optimization, virtual communication advertising, pay-per-click on marketing, content material advertising, internet analytics, and greater. These university courses are designed for students who possess a comprehensive understanding of virtual marketing strategies and attributes.Safalta Digital Marketing Institute in Noida is a first choice for young individuals or students who are looking to start their careers in the field of digital advertising. The institute gives specialized courses designed and certification.
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Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
2. GPS Standards SC3a – Discriminate between the relative size, charge, and position of protons, neutrons, and electrons in the atom. Identify the inadequacies in the Rutherford atomic model. Identify the new proposal in the Bohr model of the atom. Describe the energies and positions of electrons according to the quantum mechanical model. Describe how the shapes of orbitals related to different sublevels differ. 2
3. Essential Question How are Rutherford’s, Bohr’s, and the quantum mechanical models related to each other? 3
4. Notes Inadequacies in Rutherford’s Model Could not explain why metals and metal compounds give off characteristic colors when heated in a flame Could not explain why heated metals glow red, then yellow, then white Could not explain the chemical properties of elements Treated the electron as a particle 4
5. The Bohr Model Revised Rutherford’s model to include information about how the energy of an atom changes when it absorbs or emits light Proposed that an electron is found only in specific circular paths, or orbits, around the nucleus Each proposed orbit has a fixed energy called an energy level Higher the energy of an electron, the farther it is from the nucleus Quantum – the amount of energy required to move an electron from one energy level to another energy level Gave results in agreement with experiments for the hydrogen atom Failed to explain the energies absorbed and emitted by atoms with more than one electron Treated the electron as a particle 5
6. Quantum Mechanical Model Schrodinger Devised a mathematical equation describing electron as a wave Quantum mechanical model modern description of the electrons around an atom based on mathematical solutions to Shrödinger’s equation Based on the probability of finding an electron within a particular volume of space around the nucleus By treating the electron as an electron wave instead of a particle, most of the problems associated with Bohr’s model were alleviated. There are still some problems that we will look at later. The model is still a work in progress. 6
7. September 7, 2011 Essential Question How are quantum numbers used to describe electrons? 7
8. Quantum Numbers Each electron around an atom has a set of 4 quantum numbers which describe the “energy address” of the electron. Principal quantum number (n) First quantum number Represents the energy level in which the electron is found (larger value of n = higher energy) Determines the size of an orbital (larger value of n = larger orbital size) The values of n are successive integers beginning with 1 (n = 1, 2, 3, 4, …., ) Each energy level represents 1 period on the periodic table. Maximum number of orbitals in an energy level = n2 Maximum number of electrons in an energy level = 2n2 8
9. Angular momentum quantum number (l) Designates the shape of the orbital in which the electron is found Indicates the sublevel of the electron Values of l = successive integers from zero to n-1 (l = 0, 1, 2, …., n-1) Each energy level has a number of sublevels equal to the value of n. Energy level n=1 has 1 sublevel (l=0) Energy level n=2 has 2 sublevels (l=0 and l=1) Energy level n=3 has 3 sublevels (l=0, l=1, and l=2) Energy level n=4 has 4 sublevels (l=0, l=1, l=2, l=3) Commonly used labels of the sublevels l=0 is the s-sublevel l=1 is the p-sublevel l=2 is the d-sublevel l=3 is the f-sublevel 9
11. Magnetic quantum number (ml) Determines the orientation of the orbital within the sublevel Each energy level has an s-sublevel that contains 1 s-orbital Beginning with the 2nd energy level, each energy level has a p-sublevel containing 3 p-orbitals. Beginning with the 3rd energy level, each energy level has a d-sublevel containing 5 d-orbitals. Beginning with the 4th energy level, each energy level has an f-sublevel, containing 7 f-orbitals Values of ml are integers from –l to +l Orbital – a region in the space surrounding the nucleus where the probability of finding an electron is above 90% 11
12. Spin quantum number (ms) Each orbital can hold a maximum of 2 electrons. Spin makes the electron act like a tiny magnet Values of ms are +1/2 or -1/2 12
13. Orbital filling diagrams Show all 4 quantum numbers for each electron surrounding an atom V: 23e- 1s 2s 2p 3s 3p 4s 3d 13
14. Aufbau Principle Electrons occupy the orbitals of least energy first. Always fill one sublevel before adding electrons to a higher energy sublevel. Hund’s Rule Electrons occupy orbitals of the same energy level in a way that makes the number of electrons with the same spin direction as large as possible. Always add 1 electron to each orbital in a sublevel before adding a second electron to any orbital in that sublevel. Pauli’s Exclusion Principle No 2 electrons in the same atom can have the exact same four quantum numbers When 2 electrons occupy the same orbital, they must have opposite spins. 14
15. Complete electron configuration Shows the energy level (principal quantum number), sublevel (angular momentum quantum number) and the number of electrons in that sublevel. Coefficient = energy level Letter = sublevel Superscript = number of electrons The sum of the superscripts should equal the atomic number of the element. V: 23e- 1s22s22p63s23p64s23d3 15
16. Noble gas configuration Uses the symbol of the previous noble gas in brackets to represent the configuration of the inner energy levels Vanadium: [Ar]4s23d3 16
17. Electron-dot diagrams Shows only the electrons in the outermost energy level For elements in the s-block and p-block, the number of dots equals the last number in the group number For transition elements, the number of dots is 2 for all elements other than those in groups 6 and 11. These two groups will exhibit 1 dot. The symbol of the element represents all inner electrons. 17
18. Physics & the Quantum Mechanical Model Light Sir Isaac Newton Tried to explain light behavior by assuming that light travels as a particle but other evidence convinced scientists that light travels as a wave 18
19. Wave properties of light Amplitude – height from the equilibrium position to the crest or trough Wavelength () – distance between two crests Frequency () Number of waves that pass a given point per second Measured in hertz (Hz) 1 Hz = 1 wave per second Speed of light (c) A constant (2.998 x 108 m/s in a vacuum) c = speed of light(m/s) = wavelength(m) x frequency(Hz) Wavelength and frequency are inversely proportional (seesaw relationship) 19
20. Electromagnetic radiation Includes visible light as well as infrared, ultraviolet, gamma, x-rays, radio waves, etc. (see p. 139) Continuous spectrum All of the different frequencies of light coming from light source as seen through a prism Sunlight contains all of the frequencies of light Each color blends into the next as in a rainbow 20
21. Atomic Spectra When atoms absorb energy, electrons move into higher energy levels When electrons lose energy, they fall into lower energy levels by emitting the same amount of energy as light. 21
22. Atomic emission spectrum Each fall of an electron to a lower energy orbital represents a specific frequency of light which corresponds to a particular color. When light from an excited atom is passed through a prism, the frequencies represented by the changes in energy of the electrons are separated into distinct lines. Each line represents a single movement of an electron to a lower energy orbital. 22
24. Emission spectrum of an element is like a fingerprint for that element and can be used to identify the element. Explanation of Atomic Spectra Ground state Electrons are in their lowest possible energy states Excited state Electrons have moved into higher energy orbitals by absorbing energy Max Planck Determined the relationship between the energy of a quantum (photon) and the frequency of light. E = h h = Planck’s constant = 6.626 x 10-34 Js 24
26. Quantum Mechanics Einstein Revisited the concept of light as a particle Called a quantum of light a photon Won the nobelprize for his explanation of the photoelectric effect 26
27. de Broglie Based on the dual wave/particle nature of light, proposed a similar duality for the electron, calling the wavelike behavior of particles matter waves All moving objects exhibit wavelike behavior; however the mass must be very small in order for the wavelength to be large enough to observe. Davison and Germer Found experimental evidence to support de Broglie’s claim that electrons travel as waves Heisenberg Heisenberg Uncertainty Principle It is impossible to know exactly both the velocity and position of a particle at the same time. 27