Question

what is the formula of lead nitrate and how to find it

Answer 1

The formula of Lead Nitrate is Pb(NO3)2

How to find it?

Valency of Pb = +2
Valency of NO3 = -1

So when these two elements are joined, +2 goes to NO3 and -1 goes to Pb. Hence the final formula will be Pb(NO3)2