Statement I : The plot of atomic number (y-axis) versus number of neutrons (-r-axis) for stable nuclei

Question

Read the following questions and answer as per the direction given below : 

(a) Statement I is true; Statement II is true; Statement II is a correct explanation of Statement I. 

(b) Statement I is true; Statement II is true; Statement II is not the correct explanation of Statement I. 

(c) Statement I is true; Statement II is false. 

(d) Statement I is false; Statement tt is true.

Statement I : The plot of atomic number (y-axis) versus number of neutrons (-r-axis) for stable nuclei shows a curvature towards x-axis from the line of 45° slope as the atomic number is increased.

Statement II : Proton-proton electrostatic repulsions begin to overcome attractive forces involving protons and neutrons in heavier nuclides. 

Answer 1

The correct option (a) Statement I is true; Statement II is true; Statement II is a correct explanation of Statement I. 

Explanation:

The stability relationship can be represented by a line with a slope of 45°, ie, the maximum stability is attained when N = Z Right of the curve a radioactive nuclide would be neutron rich and would decay by β-emission to produce a daughter nucleus with a lower n/p ratio. p For heavier nuclides, p-p repulsions start to offset the attractive forces and an excess of neutrons over protons, is required for stability.