what is the symbol for chromium (II) sulfate?

Question

You mean the formula?
CrSO₄

yes! thanx!!!!!! do u know how to find the number of molecules or atoms in a mole?

The number of atoms in a mole is called Avogadro's number, the value of which is approximately 6.02 × 10^23.

There are 6.02 x 10^23 atoms in a mole of atoms, 6.02 x 10^23 molecules in a mole of molecules, 6.02 x 10^23 eggs in a mole of eggs, and in fact 6.02 x 10^23 of anythings in a mole of anything. So 6.02 x 10^23 is a number, just as we have a "dozen" eggs(meaning 12 eggs), a "gross" of pencils (meaning 144 pencils), or a ream of paper (meaning 500 sheets). So a "mole" of atoms means 6.02 x 10^23 atoms or molecules, or whatever we are talking about.