Answer:
1.29x10^22 atoms of magnesium
Explanation:
since the mass of magnesium is 5.20g and the molar mass is 24g/more and we know that 1mol of an element is equal to 6.022x10^22 atoms so we can start by finding the number of moLes of magnesium
5.20g/1 ×1mol/24.31×6.022×10^22 atoms/1mol
=1.29×10^22 atoms of magnesium