What is the percent composition of each element in magnesium permanganate?

Answer 1

To work this out you need the formula of the compound and your Periodic Table to tell you the relative atomic masses of each element.

First add up all the relative atomic masses to get the relative formula mass. Then for each element in turn, take its relative Atomic Mass (multiplying up if there is more than one of it in the formula) and divide by the relative formula mass, then multiply by 100 to get a percentage.

I'm not going to give you the answer - partly because then you'll never practise doing it for yourself, and partly because I wonder if you meant magnesium permanaganate, or the more usual school compound of potassium permanganate, KMnO4.