Question

What ions are there in Hg2(NO3)2​

Answer 1

Answer:

This formula is incorrect, as the valency of Hg is 2+ and that of NO3 is -1.

The correct formula will be Hg(NO3)2.

Answer 2

Answer:

$NO_{3} ^{2-}$ and $Hg_{2} ^{2+}$

Explanation:

The contradiction is with Hg...

actually, $Hg^{+}$ ion do not exist... it exists as dimercuric  ion in which two Hg atoms are covalently bonded.