[sam12103]

11.
Which of the following ions are unlikely to be found in a chemical compound: Cs^+; In^4+;Te^3-;P^3-?

a. Cs^+

b. In^4+

c. Te^3-

d. P^3-

e.In^4+ and Te^3-

f.In^4+ and P^3-


The answer is e. but can someone explain how to find this answer, and in general, how to approach this problem.

Thank you

[orgoclear]

Cs+ is found because it leads to the formation of an inert gas type configuration so it is extremely stable

In(4+) is not found because it exists in +1 and +3 states only (it is an element of Group III) which show oxidation states of +1 and +3 and here due to inert pair effect +1 state will be much more prevalent

Te(3-) does not exist because it deviates from ideal gas configuration (Te2-) has inert gas configuration

P(3-) exists because it has inert gas configuration