Blackbody radiation,Plank's radiation law, photoelectric effect,Compton effect,pair production,De broglie's matter wave,The concept of wave packets and group velocities, Heisenberg's uncertainty principle, application of uncertainty principle,Schrodinger
wave equation, linearity and superposition, expectation values, operators,particle in box,finite potential well, potential barrier, tunnel effect, space quantization,jj coupling,ls coupling,Zeeman effect,nuclear physics and many more
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Quantum numbers.
Quantum numbers;
In case of elementary particles, while considering reactions, we must consider various parameters. One of the major parameter is quantum numbers.
Baryon and lepton numbers
A set of quantum numbers is used to characterise baryons and three families of leptons.
Baryon and lepton numbers.
The significance of these numbers is that in any kind of reaction the total baryon numbers (B) and lepton numbers are conserved.
Baryon and lepton quantum numbers are conserved.
Strangeness number (S)
Gellmann and Nishijina introduced a new quantum number called strangeness quantum number. Strangeness number is assigned to strange particles, which are named due to their strange behaviour i.e they are produced via strong interaction or electromagnetic interaction, but they decay via weak interaction. Another fact about these particles is that they are always produced in pairs. The assignment of strangeness number to particle is shown in Table below.
Strangeness number of hadrons.
The antiparticles have the S value negative of shown above.
Strangeness number (S) are conserved in all process mediated by strong and electromagnetic interactions. Example in proton - proton collision.
Mass defect, packing fraction and binding energy: It was assumed that mass of the nucleus is equal to the mass of its constituents (i.e protons and neutrons). But experimentally it was found that the actual mass of the nucleus is less than the theoretical mass. Thus, the difference between the theoretical mass and experimental mass is called mass defect i.e ∆m={[Zmₚ + (A-Z)mₙ] - M} Where mₚ= mass of proton mₙ= mass of neutron M= actual mass of nucleus Z= atomic number A= mass number The ratio of mass defect and mass number (A) is called packing fraction (f) f = ∆m/A Thus packing fraction is the mass defect available per nucleon. The packing fraction explains the stability of the nucleus. The packing fraction may be positive, negative or zero. The positive value of packing fract...
Different kinds of beta decay 1) Negative beta decay process: When there is excess number of neutrons in the nucleus, the neutron is converted into proton with the emission of electron and antineutrino particle and this process is called negative beta decay process. Negative beta decay. 2) Positive beta decay process: When there is excess number of protons in the nucleus, the proton is converted into neutron with the emission of positron and neutrino particle and this process is called positive beta decay process. Positive beta decay. 3) Electron Capture: When there is excess number of protons in the nucleus, sometimes the nucleus will absorbed the nearby electrons in the nearest electron orbital emitting neutron and a neutrino and this process is called electron capture. Electron capture. 4) Inverse beta decay: Inverse beta decay. Thus such kind of reaction in which neutrinos are absorbed to create some sort of beta decay is called inverse beta decay. Inverse beta decay confirm t...
Total angular momentum: The total angular momentum of an electron is the sum of the orbital angular momentum and spin angular momentum of the electron i.e Coupling Scheme Since an atom consist of large number of electrons having different orbital and spin momenta, Coupling scheme is necessary to obtain the resultant orbit and spin momenta of atom as a whole. There are two types of coupling scheme namely 1) LS Coupling 2) JJ Coupling. 1)LS Coupling: In this coupling the 'l' vectors of all electrons combine to form resultant 'L' vector and all the 's' vectors of these electrons combine to form resultant 'S' vector. Then the 'L' vector and 'S' vector undergoes vector addition to give resultant 'J' vector which represents the total angular momentum of an atom. Symbolically LS coupling is represented as This type of coupling is governed by the following principles: 1) All the three vectors (L,S and J vectors) are quantized. 2)L is an ...
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