Given the number of Mg atoms is [tex] 7.43 * 10^{22} atoms [/tex]
We know that 1 mol of any substance has Avogadro number [tex] (6.022 * 10^{23}) [/tex] of formula units.
Converting number of atoms to mol:
[tex] 7.43 * 10^{22} atoms * \frac{1 mol}{6.022*10^{23} atoms} = 0.123 mol Mg [/tex]
Converting mol to mass of Mg:
[tex] 0.123 mol * \frac{24.30 g}{1 mol} = 2.99 g Mg [/tex]
Therefore mass of Mg is 2.99 g
