Question

108. Ionisation energies of element A are given below
KJ/mol :
IE
IE 2
IE 3
120
430
540
If A react with different elements, which compounds
of A is not possible ?
(a) AF
(b) A20 (c) AZN (d) A3N2​

Answer 1

Answer:

Third ionization energy (13000 kJ/mol) is much higher than the second ionization energy (430 kJ/mol). This indicates alkaline earth metal with 2 valence electrons. When 2 valence electrons are removed, the stable electronic configuration of inert gas is obtained. When the third electron is lost, the stable electronic configuration of inert gas is broken. This requires a large amount of energy. Hence, the third ionization energy is very high.

The valency of alkaline earths is +2. It forms A

2+

ions.The valence of N is −3.It forms N

3−

ions.Thus, A will react with N to form A

3

N

2

.With F, A will form AF

2

. With O, A will form AO .