A sample of a substance containing only magnesium and chlorine was tested in the lab and was found to be composed of 74.5% chlor
ine by mass. If the total mass of the sample was 190.2 grams, what was the mass of the magnesium? A) 24.3 g B) 48.5 g
C) 70.9 g D) 142 g
I know the answer is B, but I don't understand why.....
