Question

a compound is formed when 9.03 Mg combines completely with 3.48g N. what is the percent composition of this compound?

Answer 1

First, add the two together, which is 12.51
Then find the percent of each in the 12.51
So for Mg: 9.03/12.51=0.72
And N: 3.48/12.51=0.28

So the compound is 72% magnesium and 28% nitrogen.
Hope this helps! :)