(a) The mass of a nucleus in its ground state is always less than total mass of its constituents - neutrons and protons. Explain.
(b) Plot a graph showing the variation of potential energy of a pair of nucleons as a function of their separation.

(a) In a nuclear reaction ""_(2)^(3)He +""_(2)^(3)He to ""_(2)^(4)He+""_(1)^(1)H +""_(1)^(1)H +12.86 MeV, though the number of nucleons is conserved on both sides of the reaction, yet the energy is released. How? Explain. (b) Draw a plot of potential energy between a pair of nucleons as a function of their separation. Mark the regions where potential energy is (i) positive and (ii) negative.

The mass of ._3^7Li is 0.042 amu less than the sum of masses of its constituents. The binding energy per nucleon is

A rod of length L and mass m is kept vertically on the ground. Its potential energy is :

Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?

The total energy of a hydrogen atom in its ground state is -13.6 eV . If the potential energy in the first excited state is taken as zero then the total energy in the ground state will be

Using the conservation laws, demonstrate that the total mechanical energy of a planet of mass m moving around the Sun along an ellipse depends only on its semi-major axis a. Find this energy as a function of a.

The experimentally determined molar mass for what type ofsubstances is always lower than the true value when water is used as solvent. Explain. Give one example of such a substance and one example of a substance which does not show a large variation from the true value.

M, M_(n) & M_(p) denotes the masses of a nucleous of ._(Z)X^(A) a neutron, and a proton respectively. If the nucleus is separated in to its individual protons and neutrons then

Sulphur has an atomic number 16 and a mass number of 32. State the number of protons and neutrons in the nucleus of sulphur. Give a simple diagram to show the arrangement of electrons in an atom of sulphur.