Question

What is meant by the term ‘variable valency’. Give a reason why silver exhibits a valency of +1 and +2.

Answer 1

Variable valency: “Certain elements exhibit more than one valency and show variable valency.”

Reason: Why silver exhibits valency +1 and +2 Ag 47 [2, 8, 18, 18, 1] has 1 electron in the outermost shell when loses this electron shows [+1] valency but when the penultimate shell has not attained stability and one more electron jumps to the outermost shell thereby increasing valency electron and new configuration [2, 8, 18, 17, 2] loses two electrons and has valency [+2]
∴ Silver exhibits Ag¹⁺ [ous] and Ag²⁺ [ic]