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.
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 ...
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...
Photoelectric effect; The emission of electrons by a substance under the action of light is called Photoelectric effect. Photoelectric Effect. Experimental Setup: The phenomenon of photoelectric effect can be studied with the help of an apparatus shown in Figure below. Within an evacuated glass jacket two electrodes R and S are enclosed and the light radiation is allowed to enter the jacket through a quartz window. The radiation falls on electrode R, called cathode. The electrode S can be kept at desired (positive or negative) potential with respect to the cathode. A sensitive ammeter is put in the circuit to record current resulting from photoelectrons. The potential difference between the cathode and anode can be measured by voltmeter . Experimental Setup. Experimental observations The experimental observation of photoelectric effect may be summarised as follows; 1) Effect of Intensity of light on Photoelectric current; For a constant potential difference between the cathode ...
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