Waht are the reletive number of atoms in these compounds?

Question

Calcium:

iodine:

Zinc:

Bromine:

Magnesium:

Sulphur:

Answer 1

Take the mass (g/mol) and divide my avagadro's number (6.022x10^23)

Answer 2

not exactly sure what you want but here's what i can tell you
Iodine and bromine are diatomic and have 2 atoms in a molecule
Sulfur has an alitropic form that has 8 atoms in the molecule.
Magnesium and Zinc are monatomic and have only 1 atom that makes up their molecules