Answer:
The answers to your questions are given below
Explanation:
1. 3 Na2SO4
Molecules of Na2SO4 = 3
Na (sodium) = 3 x 2 = 6
S (sulphur) = 3 x 1 = 3
O (oxygen) = 3 x 4 = 12
2. 4 Pb(NO3)2
Molecules of Pb(NO3)2 = 2
Pb (lead) = 4 x 1 = 4
N (nitrogen) = 4 x 2 x 1 = 8
O (oxygen) = 4 x 3 x 2 = 24
