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intrinsic magnetic field : the magnetic field generated due to the intrinsic spin of electrons | https://openstax.org/books/college-physics-2e/pages/30-glossary |
intrinsic spin : the internal or intrinsic angular momentum of electrons | https://openstax.org/books/college-physics-2e/pages/30-glossary |
laser : acronym for light amplification by stimulated emission of radiation | https://openstax.org/books/college-physics-2e/pages/30-glossary |
magnitude of the intrinsic (internal) spin angular momentum : given byS=ss+1h2ÏS=ss+1h2Ï | https://openstax.org/books/college-physics-2e/pages/30-glossary |
metastable : a state whose lifetime is an order of magnitude longer than the most short-lived states | https://openstax.org/books/college-physics-2e/pages/30-glossary |
orbital angular momentum : an angular momentum that corresponds to the quantum analog of classical angular momentum | https://openstax.org/books/college-physics-2e/pages/30-glossary |
orbital magnetic field : the magnetic field generated due to the orbital motion of electrons | https://openstax.org/books/college-physics-2e/pages/30-glossary |
Pauli exclusion principle : a principle that states that no two electrons can have the same set of quantum numbers; that is, no two electrons can be in the same state | https://openstax.org/books/college-physics-2e/pages/30-glossary |
phosphorescence : the de-excitation of a metastable state | https://openstax.org/books/college-physics-2e/pages/30-glossary |
planetary model of the atom : the most familiar model or illustration of the structure of the atom | https://openstax.org/books/college-physics-2e/pages/30-glossary |
population inversion : the condition in which the majority of atoms in a sample are in a metastable state | https://openstax.org/books/college-physics-2e/pages/30-glossary |
quantum numbers : the values of quantized entities, such as energy and angular momentum | https://openstax.org/books/college-physics-2e/pages/30-glossary |
Rydberg constant : a physical constant related to the atomic spectra with an established value of1.097Ã107mâ11.097Ã107mâ1 | https://openstax.org/books/college-physics-2e/pages/30-glossary |
shell : a probability cloud for electrons that has a single principal quantum number | https://openstax.org/books/college-physics-2e/pages/30-glossary |
space quantization : the fact that the orbital angular momentum can have only certain directions | https://openstax.org/books/college-physics-2e/pages/30-glossary |
spin projection quantum number : quantum number that can be used to calculate the intrinsic electron angular momentum along thezz-axis | https://openstax.org/books/college-physics-2e/pages/30-glossary |
spin quantum number : the quantum number that parameterizes the intrinsic angular momentum (or spin angular momentum, or simply spin) of a given particle | https://openstax.org/books/college-physics-2e/pages/30-glossary |
stimulated emission : emission by atom or molecule in which an excited state is stimulated to decay, most readily caused by a photon of the same energy that is necessary to excite the state | https://openstax.org/books/college-physics-2e/pages/30-glossary |
subshell : the probability cloud for electrons that has a single angular momentum quantum numberll | https://openstax.org/books/college-physics-2e/pages/30-glossary |
x rays : a form of electromagnetic radiation | https://openstax.org/books/college-physics-2e/pages/30-glossary |
x-ray diffraction : a technique that provides the detailed information about crystallographic structure of natural and manufactured materials | https://openstax.org/books/college-physics-2e/pages/30-glossary |
z-component of spin angular momentum : component of intrinsic electron spin along thezz-axis | https://openstax.org/books/college-physics-2e/pages/30-glossary |
z-component of the angular momentum : component of orbital angular momentum of electron along thezz-axis | https://openstax.org/books/college-physics-2e/pages/30-glossary |
Zeeman effect : the effect of external magnetic fields on spectral lines | https://openstax.org/books/college-physics-2e/pages/30-glossary |
Atoms are the smallest unit of elements; atoms combine to form molecules, the smallest unit of compounds. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The first direct observation of atoms was in Brownian motion. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Analysis of Brownian motion gave accurate sizes for atoms (10â10m10â10mon average) and a precise value for Avogadroâs number. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Atoms are composed of negatively charged electrons, first proved to exist in cathode-ray-tube experiments, and a positively charged nucleus. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
All electrons are identical and have a charge-to-mass ratio ofqeme=â1.76Ã1011C/kg.qeme=â1.76Ã1011C/kg. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The positive charge in the nuclei is carried by particles called protons, which have a charge-to-mass ratio ofqpmp=9.57Ã107C/kg.qpmp=9.57Ã107C/kg. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Mass of electron,me=9.11Ã10â31kg.me=9.11Ã10â31kg. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Mass of proton,mp=1.67Ã10â27kg.mp=1.67Ã10â27kg. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The planetary model of the atom pictures electrons orbiting the nucleus in the same way that planets orbit the sun. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The planetary model of the atom pictures electrons orbiting the nucleus in the way that planets orbit the sun. Bohr used the planetary model to develop the first reasonable theory of hydrogen, the simplest atom. Atomic and molecular spectra are quantized, with hydrogen spectrum wavelengths given by the formula1λ=R1nf2... | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The constantsniniandnfnfare positive integers, andninimust be greater thannfnf. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Bohr correctly proposed that the energy and radii of the orbits of electrons in atoms are quantized, with energy for transitions between orbits given byÎE=hf=EiâEf,ÎE=hf=EiâEf,whereÎEÎEis the change in energy between the initial and final orbits andhfhfis the energy of an absorbed or emitted photon. It is usefu... | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Bohr proposed that the allowed orbits are circular and must have quantized orbital angular momentum given byL=mevrn=nh2Ïn=1, 2, 3 â¦,L=mevrn=nh2Ïn=1, 2, 3 â¦,whereLLis the angular momentum,rnrnis the radius of thenthnthorbit, andhhis Planckâs constant. For all one-electron (hydrogen-like) atoms, the radius of an ... | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Furthermore, the energies of hydrogen-like atoms are given byEn=âZ2n2E0n=1, 2, 3 ...,En=âZ2n2E0n=1, 2, 3 ...,whereE0E0is the ground-state energy and is given byE0=2Ï2qe4mek2h2=13.6 eV.E0=2Ï2qe4mek2h2=13.6 eV.Thus, for hydrogen,En=â13.6 eVn2n=1, 2, 3 ....En=â13.6 eVn2n=1, 2, 3 .... | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The Bohr Theory gives accurate values for the energy levels in hydrogen-like atoms, but it has been improved upon in several respects. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
X rays are relatively high-frequency EM radiation. They are produced by transitions between inner-shell electron levels, which produce x rays characteristic of the atomic element, or by decelerating electrons. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
X rays have many uses, including medical diagnostics and x-ray diffraction. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
An important atomic process is fluorescence, defined to be any process in which an atom or molecule is excited by absorbing a photon of a given energy and de-excited by emitting a photon of a lower energy. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Some states live much longer than others and are termed metastable. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Phosphorescence is the de-excitation of a metastable state. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Lasers produce coherent single-wavelength EM radiation by stimulated emission, in which a metastable state is stimulated to decay. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Lasing requires a population inversion, in which a majority of the atoms or molecules are in their metastable state. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Quantization of orbital energy is caused by the wave nature of matter. Allowed orbits in atoms occur for constructive interference of electrons in the orbit, requiring an integral number of wavelengths to fit in an orbitâs circumference; that is,nλn=2Ïrnn=1, 2, 3 ...,nλn=2Ïrnn=1, 2, 3 ...,whereλnλnis the electr... | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Owing to the wave nature of electrons and the Heisenberg uncertainty principle, there are no well-defined orbits; rather, there are clouds of probability. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Bohr correctly proposed that the energy and radii of the orbits of electrons in atoms are quantized, with energy for transitions between orbits given byÎE=hf=EiâEf,ÎE=hf=EiâEf,whereÎEÎEis the change in energy between the initial and final orbits andhfhfis the energy of an absorbed or emitted photon. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
It is useful to plot orbit energies on a vertical graph called an energy-level diagram. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The allowed orbits are circular, Bohr proposed, and must have quantized orbital angular momentum given byL=mevrn=nh2Ïn=1, 2, 3 ...,L=mevrn=nh2Ïn=1, 2, 3 ...,whereLLis the angular momentum,rnrnis the radius of orbitnn, andhhis Planckâs constant. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The Zeeman effectâthe splitting of lines when a magnetic field is appliedâis caused by other quantized entities in atoms. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Both the magnitude and direction of orbital angular momentum are quantized. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The same is true for the magnitude and direction of the intrinsic spin of electrons. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
Quantum numbers are used to express the allowed values of quantized entities. The principal quantum numbernnlabels the basic states of a system and is given byn=1,2,3,....n=1,2,3,.... | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The magnitude of angular momentum is given byL=ll+1h2Ïl=0, 1, 2, ...,nâ1,L=ll+1h2Ïl=0, 1, 2, ...,nâ1,wherellis the angular momentum quantum number. The direction of angular momentum is quantized, in that its component along an axis defined by a magnetic field, called thezz-axis is given byLz=mlh2Ïml=âl,âl+1,... | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The state of a system is completely described by a complete set of quantum numbers. This set is written asn, l,ml,msn, l,ml,ms. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The Pauli exclusion principle says that no two electrons can have the same set of quantum numbers; that is, no two electrons can be in the same state. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
This exclusion limits the number of electrons in atomic shells and subshells. Each value ofnncorresponds to a shell, and each value ofllcorresponds to a subshell. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The maximum number of electrons that can be in a subshell is22l+122l+1. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
The maximum number of electrons that can be in a shell is2n22n2. | https://openstax.org/books/college-physics-2e/pages/30-section-summary |
activity : the rate of decay for radioactive nuclides | https://openstax.org/books/college-physics-2e/pages/31-glossary |
alpha decay : type of radioactive decay in which an atomic nucleus emits an alpha particle | https://openstax.org/books/college-physics-2e/pages/31-glossary |
alpha rays : one of the types of rays emitted from the nucleus of an atom | https://openstax.org/books/college-physics-2e/pages/31-glossary |
antielectron : another term for positron | https://openstax.org/books/college-physics-2e/pages/31-glossary |
antimatter : composed of antiparticles | https://openstax.org/books/college-physics-2e/pages/31-glossary |
atomic mass : the total mass of the protons, neutrons, and electrons in a single atom | https://openstax.org/books/college-physics-2e/pages/31-glossary |
atomic number : number of protons in a nucleus | https://openstax.org/books/college-physics-2e/pages/31-glossary |
barrier penetration : quantum mechanical effect whereby a particle has a nonzero probability to cross through a potential energy barrier despite not having sufficient energy to pass over the barrier; also called quantum mechanical tunneling | https://openstax.org/books/college-physics-2e/pages/31-glossary |
becquerel : SI unit for rate of decay of a radioactive material | https://openstax.org/books/college-physics-2e/pages/31-glossary |
beta decay : type of radioactive decay in which an atomic nucleus emits a beta particle | https://openstax.org/books/college-physics-2e/pages/31-glossary |
beta rays : one of the types of rays emitted from the nucleus of an atom | https://openstax.org/books/college-physics-2e/pages/31-glossary |
binding energy : the energy needed to separate nucleus into individual protons and neutrons | https://openstax.org/books/college-physics-2e/pages/31-glossary |
binding energy per nucleon : the binding energy calculated per nucleon; it reveals the details of the nuclear forceâlarger theBE/ABE/A, the more stable the nucleus | https://openstax.org/books/college-physics-2e/pages/31-glossary |
carbon-14 dating : a radioactive dating technique based on the radioactivity of carbon-14 | https://openstax.org/books/college-physics-2e/pages/31-glossary |
chart of the nuclides : a table comprising stable and unstable nuclei | https://openstax.org/books/college-physics-2e/pages/31-glossary |
curie : the activity of 1g of226Ra226Ra, equal to3.70Ã1010Bq3.70Ã1010Bq | https://openstax.org/books/college-physics-2e/pages/31-glossary |
daughter : the nucleus obtained when parent nucleus decays and produces another nucleus following the rules and the conservation laws | https://openstax.org/books/college-physics-2e/pages/31-glossary |
decay : the process by which an atomic nucleus of an unstable atom loses mass and energy by emitting ionizing particles | https://openstax.org/books/college-physics-2e/pages/31-glossary |
decay constant : quantity that is inversely proportional to the half-life and that is used in equation for number of nuclei as a function of time | https://openstax.org/books/college-physics-2e/pages/31-glossary |
decay equation : the equation to find out how much of a radioactive material is left after a given period of time | https://openstax.org/books/college-physics-2e/pages/31-glossary |
decay series : process whereby subsequent nuclides decay until a stable nuclide is produced | https://openstax.org/books/college-physics-2e/pages/31-glossary |
electron capture : the process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino | https://openstax.org/books/college-physics-2e/pages/31-glossary |
electron capture equation : equation representing the electron capture | https://openstax.org/books/college-physics-2e/pages/31-glossary |
electronâs antineutrino : antiparticle of electronâs neutrino | https://openstax.org/books/college-physics-2e/pages/31-glossary |
electronâs neutrino : a subatomic elementary particle which has no net electric charge | https://openstax.org/books/college-physics-2e/pages/31-glossary |
gamma decay : type of radioactive decay in which an atomic nucleus emits a gamma particle | https://openstax.org/books/college-physics-2e/pages/31-glossary |
gamma rays : one of the types of rays emitted from the nucleus of an atom | https://openstax.org/books/college-physics-2e/pages/31-glossary |
Geiger tube : a very common radiation detector that usually gives an audio output | https://openstax.org/books/college-physics-2e/pages/31-glossary |
half-life : the time in which there is a 50% chance that a nucleus will decay | https://openstax.org/books/college-physics-2e/pages/31-glossary |
ionizing radiation : radiation (whether nuclear in origin or not) that produces ionization whether nuclear in origin or not | https://openstax.org/books/college-physics-2e/pages/31-glossary |
isotopes : nuclei having the sameZZand differentNNs | https://openstax.org/books/college-physics-2e/pages/31-glossary |
magic numbers : a number that indicates a shell structure for the nucleus in which closed shells are more stable | https://openstax.org/books/college-physics-2e/pages/31-glossary |
mass number : number of nucleons in a nucleus | https://openstax.org/books/college-physics-2e/pages/31-glossary |
neutrino : an electrically neutral, weakly interacting elementary subatomic particle | https://openstax.org/books/college-physics-2e/pages/31-glossary |
neutron : a neutral particle that is found in a nucleus | https://openstax.org/books/college-physics-2e/pages/31-glossary |
nuclear radiation : rays that originate in the nuclei of atoms, the first examples of which were discovered by Becquerel | https://openstax.org/books/college-physics-2e/pages/31-glossary |
nuclear reaction energy : the energy created in a nuclear reaction | https://openstax.org/books/college-physics-2e/pages/31-glossary |
nucleons : the particles found inside nuclei | https://openstax.org/books/college-physics-2e/pages/31-glossary |
nucleus : a region consisting of protons and neutrons at the center of an atom | https://openstax.org/books/college-physics-2e/pages/31-glossary |
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