) Paragraph The mass of a nucleus ZXA is less than the sum of the masses of (A-Z) number of neutronsand Z number of protons in the nucleus. The energy equivalent to the corresponding massdifference is known as the binding energy of the nucleus. A heavy nucleus of mass M canbreak into two light nuclei of masses m1 and m2 only if (m1 + m2) < M. Also two light nucleiof masses m3 and m4 can undergo complete fusion and form a heavy nucleus of mass M′ only if (m3 + m4) > M′. The masses of some neutral atoms are given in the table below : The correct statement is

1H1	1.007825 u	1H2	2.014102 u
1H3	3.016050u	2He4	4.002603u
3Li6	6.015123 u	3Li7	7.016004 u
30Zn70	69.925325u	34Se82	81.916709u
64Gd152	151.919803u	82Pb206	205.974455u
83Bi209	208.980388u	84Po210	209.982876u

The kinetic energy (in keV) of the alpha particle, when the nucleus 84Po210 at restundergoes alpha decay, is

Match List I of the nuclear processes with List II containing parent nucleus and one of the end products of each process and then select the correct answer using the codes given below the lists:

List I	List II
P. Alpha decay	8O15 → 7N15+ ....
Q. β+ decay	92U238 → 90Th234+ ....
R. Fission	83Bi185 → 82Pb184+ ....
S. Proton emission	94Pu239 → 57La140+ ...

)If λCu is the wavelength of Kα X-ray line of copper (atomic number 29) and λMo is the wavelength of the Kα X-ray line of molybdenum (atomic number 42), then the ratio λCu /λMo is close to

A fission reaction is given by 92U236→ 54Xe140 + 38Sr94+x+y,where x and y are two particles. Considering 92U236 to be at rest, the kinetic energies of the products are denoted by KXe, KSr, Kx (2 MeV) and Ky (2 MeV), respectively. Let the binding energies per nucleon of 92U236,54Xe140,38Sr94 be 7.5 MeV, 8.5 MeV and 8.5 MeV, respectively. Considering different conservation laws, the correct option(s) is (are)

Highly excited states for hydrogen-like atoms (also called Rydberg states) with nuclear charge Ze are defined by their principal quantum number n, where n >>Which of the following statement(s) is(are) true? [ IIT Advance 2016]

P is the probability of finding the 1s electron of hydrogen atom in a spherical shell of infinitesimal thickness, dr, at a distance r from the nucleus. The volume of this shell is 4πr2 dr. The qualitative sketch of the dependence of P on r is… [ IIT Advance 2016]

The electrostatic energy of Z protons uniformly distributed throughout a spherical nucleus of radius R is given by The measured masses of the neutron , 1H1, 7N15 and 8O15, are 1.008665 u, 1.007825 u, 15.000109 u and 15.003065 u, respectively. Given that the radii of both the and nuclei are same, 1 u = 931.5 MeV/c2 (c is the speed of light) and e2/(4πε0 ) = 1.44 MeVfm Assuming that the difference between the binding energies of 7N15 and 8O15 is purely due to the electrostatic energy, the radius of either of the nuclei is …[IIT Advance 2016] (1 fm = 10-15 m)

An accident in a nuclear laboratory resulted in deposition of a certain amount of radioactive material of half-life 18 days inside the laboratory. Tests revealed that the radiation was 64 times more than the permissible level required for safe operation of the laboratory. What is the minimum number of days after which the laboratory can be considered safe for use? [IIT Advance 2016]