Derive the molecular formula for Copper $(II)$ Bromide.

(N/A) To derive the molecular formula for Copper $(II)$ Bromide,follow these steps:
$1$. Identify the symbols of the elements involved: Copper is represented by $Cu$ and Bromide is represented by $Br$.
$2$. Determine the valency or charge of each ion: Copper $(II)$ indicates a charge of $+2$ $(Cu^{2+})$,and Bromide has a charge of $-1$ $(Br^-)$.
$3$. Use the criss-cross method to balance the charges: The charge of Copper $(2)$ becomes the subscript for Bromide,and the charge of Bromide $(1)$ becomes the subscript for Copper.
$4$. Write the formula: By crossing the charges,we get $Cu_1Br_2$,which is written as $CuBr_2$.