Question

Please explain if the following are true or false and how you got your answer.

A. The electrostatic energy of two charged particles is inversely proportional to the distance between them.

B. When comparing Lithium, sodium and oxygen, lithium has the largest second ionization energy.

C. According to the postulates of kinetic-molecular theory, the molecules of all gases at a given temperature have the same average speed.

Answer 1

(A) TRUE

Electrostatic potential energy is given by, k* q1*q2 / r
(B) TRUE

Reason:

After first ionisation energy,

Li⁺ (Z=3) electronic configuration is 1s2 it has He cofiguration which is more stable and has only one shell which has straong effective nuclear char on it.

Na⁺ (Z=11) electronic configuration is 1s2 2s2 2p6 it has Ne configuration which is some how larger in size than He so requires less energy to remove electron from it.

O⁺(Z=8) electronic configuration is 1s2 2s2 2p3 it is not the stable configuration requires less energy to remove second electron.
(C) TRUE

According to kinetic molecular theory of gases,

Kinetic energy of all the gases depends only the temperature but not on the nature of gas.

So the average speed of molecules of different gases are same at same temperature.