The mass number of an element in a radioactive series is 223. The radioactive series is
Mass number of radioactive element = 223
This mass number can be written in the form of 4n + 2, which coresponds to Uranium series.
A nucleus having mass number A decays by α - emission to the ground state of its daughter nucleus. The Q value of the process is E. The energy of the a - particle is
For α -particle emission, the kinetic energy of α -particle is given by
Kinetic Energy = Q x where Q is energy released during α - decay process.
Assuming that a nucleus is a sphere of nuclear matter of radius 1.2 x A1/3 fm, the average nucleon density in S.l. units is; approximately
The radius of nuclear matter is given by
The nucleon density
The ratio of radii of U238 and He4 nuclei is_______________(upto one decimal place)
Mass of α - particle = 4.002603 amu, mass of proton = 1.007825 amu, mass of neutron = 1.008664 amu. Taking 1 amu = 931 MeV, the binding energy of a-panicle is________(upto two decimal places).
Binding energy o f a -particle
The empirical mass formula (neglecting a term representing the odd-even effect) is
where α, β, γ and ε are constants. The expression for the value of Z which corresponds to the most stable nucleus for a set of isobars of mass number A is
The radius of G e is measured to be twice the radius of 4Be9. The number of nucleons in Ge is
The radius of Ge = 2 x radius of 4Be9.
Which one of the following statement regarding neutrino is wrong?
Neutrino has spin-1/2,. zero charge (neutral), zero rest mass and does not interact with matter.
The half life of radon ls 3.8 days. After 15.2 days, N0 /N will be________
For Radon, T1/2 = 3.8 days
Now, number of half lives in 15.2 days = 15.2/ 3.8 = 4
The Q-value of the 3H(p,n)3 He reaction is -0.764 MeV. The threshold energy (for appearance of neutrons in the forward direction is___________MeV. (upto two decimal places)
The threshold energy for apperance of neutron in the forward direction is
The distance of closest approach of α -particles to the Copper nucleus (Z = 29). when a-particles of 5 MeV energy are scattered back by a thin sheet of Copper, is
Let the distance of closest approach of α - particle to copper nucleus is b.
Al are mirror nuclei. Tlie former is a position emitter with Emax = 3.48 MeV. The value of radius constant (r0) can be estimated as
For positron emission,
The expected value of shell-model quadmpole moment of209Bi. if the ground state spin-parity of209Bi is 9-/2
The spin of 209 Bi 9/2
If the binding energies of the mirror nuclei 21Sc41 and 20Ca41 are 343.143 MeV and 350.420 MeV, respectively. The radii of these nuclei by using the semi-empirical mass formula is__________fm (upto two decimal places)
Difference in binding energies of 21Sc41 and 20Ca41 = 350.420 - 343.143 = 7.277 MeV
Since, Difference in binding energies of min or nuclei 21Se41 and 20Ca41 is equal to difference in Coulomb energies.
Using semi-empirical mass formula, the most stable isobar with mass number A = 65. corresponds to
F or A = 65, the most stable isobar corresponds to
From the shell model prediction, the ground state spin and parity of nuclei, respectively.
The shell structure of neutrons:
Therefore, last neutrons lies in shell.
Therefore, the nuclear spin of
The parity of
Hence, nuclear spin-parity of
The last proton lies in shell.
Hence, the nuclear spin-parity of
The following interactions proceed through the strong, electromagnetic (EM) or weak interactions.
The correct order of interactions is
is allowed via EM interaction because photon is involved.
is allowed via weak interaction because neutrino (Lepton) is involved.
is allowed via strong interaction because Barvons are involved.
Which one of the following reaction is NOT forbidden ?
(a) forbidden because energy is not conserved.
(b) forbidden because Baryon number is violated.
(c) allowed by strong interaction because ΔS = 0 and other quantum numbers are conserved.
(d) forbidden because Lepton number is not conserved.
Consider the decay of K° meson of momentum P0 into ,π+ and π- of momenta p+ and p_ m the opposite direction such that p+ = 2p_. The value of p0 is given by
Squaring both sides,
The ground state magnetic moment of 33S16 is_____________μN.
The nucleus has 16 protons and 17 neutrons.
The shell structure of neutrons:
Since, last neutron lies in shell.
Therefore, the nuclear spin
The magnetic moment of last neutron in state is given by