1) "Thorium" has highest half life period and "Polonium" has shortest half life period.
2) Elements lying beyond 92U238 in periodic table are called "Transuranic" elements.
3) Effective Multiplication Factor Ke = P/(A+L); 'P' is Production of Neutrons; 'A' is Rate of absorption of Neutrons; 'L' is Rate of Leakage of neutrons.
Ke = 1 -----------------------chain reaction is "Critical"
Ke > 1 -----------------------chain reaction is "Super-Critical"
Ke < 1 -----------------------chain reaction is "Sub-Critical"
Ke =NF/(A+L) as P=NF; F is rate at which Fission occur; N is average number of Neutrons emitted per Fission
Control Rods are used to keep Ke = 1
4) Slow Neutrons (Thermalized) are efficient in causing Nuclear Reaction.
5) Atoms having same 'Z' and 'A' but differ from one another in their Nuclear energy states and exhibit differences in internal structure. These Nuclei are distinguished by their different life times. Such Nuclei are called "Isomers".
6) Nuclei having same 'A' but with Proton & Neutron number interchanged (i.e. No. of Protons in one is equal to No. of Neutrons in other) re called "Mirror nuclei". For instance, 4Be7 (Z=4 and N=3), 3Li7(Z=3 & N=4).
7) Law governing successive disintegration deals with quantity of daughter nuclei present at any instant.
8) Formation of daughter element depends on decay constant of parent.
9) Decay of daughter element depends on decay constant of itself.
13) Age of rocks may be estimated with comparing quantities of various isotopes of Lead existing in sample.
14) In “ GM Region", ionization current is independent of initial ionization.
15) 35 eV is required for producing an ion pair.
14) Proportional region is most suitable for proportional counters in which number of pulses increases almost linearly with voltage.
15) Plateau region is most suitable for “ GM counter “ in which number of impulses remain constant. This region is function of Voltage , Resistance, nature of gas.
16) “quenching agent " should have “ Low Ionization Potential".
17) “ Scintillation" counter depends on principle of “ fluorescence”.
18) “ Solid state detector " depends on following principle : incoming particles into depletion region must lose all their Kinetic Energy.
19) Non integrating ionization chamber - a pulse type; Integrating Ion chamber works in current mode.
20) "GM counter" cannot be used to detect ɑ- particles.
21) “Cloud chamber “ cannot be used to detect ‘𝛾 ‘ rays.
22) By counting drops in cloud track , specific ionization can be determined.
23) Particle disintegration process ---- outgoing particle is material particle
24) Simple capture process -- outgoing particles are -γ -rays.
25) Particle disintegration process is more probable than simple capture process.
'M₀' is mass of target nucleus (A)
'M₁E₁' is Mass and Energy of projectile(B)
'M₂E₂' is Mass and Energy of product nucleus (P)
'M₃E₃' is Mass and Energy of outgoing particle(O)
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