If 2.00 g of element G reacts with 5.00 g of element M to produce 7.00 g of a compound with the formula G3M2, what is the atomic mass of G if the atomic mass of M is 135.0 amu?

Answer is 36 amu but why

2 answers

3G +2M ==> G3M2

mols M = 5.00/135 = approx 0.037
mols G = 0.037 x (3 mols G/2 mols M) = approx 0.0555

Then mols = g/atomic mass. You know mols G and grams G, solve for atomic mass G. I'll bet you get 36.
this man is a savage ^