The chemical formula for Zinc phosphate is:
$\mathrm{A}: {\mathrm{Zn}}_3({\mathrm{PO}}_4{)}_2$
$\mathrm{B}: \mathrm{Zn}({\mathrm{PO}}_4{)}_2$
$\mathrm{C}: {\mathrm{Zn}}_2({\mathrm{PO}}_4{)}_3$
Give your answer as $\mathrm{A}, \mathrm{B} \mathrm{or} \mathrm{C}$.

The chemical formula for Iron (lll) carbonate can be-

A. ${\mathrm{Fe}}_2({\mathrm{CO}}_3{)}_3$

B. $\mathrm{Fe}({\mathrm{CO}}_3{)}_3$

C. ${\mathrm{Fe}}_2{\mathrm{CO}}_3$

"Enter your correct answer as A, B or C."

Calculate the mass of $6.022 \mathrm{x} {10}^{23}$ atoms of copper.