Question

which of the following exhibits variable valency<br /><br />1.sodium<br /><br />2.hydrogen<br /><br />3.sulpher<br /><br />4.alluminium

Answer 1

I think It's Sulphur.Some of its form are Sulphide,Sulphate,Sulphite,..

Answer 2

Copper-1,2

Silver-1,2

Mercury-1,2