Answer:
The subscript is 4
Explanation:
The given molecule is written as:
[tex]5PO_{4}^{-2}[/tex]
Therefore, the subscript is 4
The coefficient is 5.
The significance of [tex]5PO_{4}^{-2}[/tex] is 5 molecules of [tex]PO_{4}^{-2}[/tex]
The number of molecules is 5 because the coefficient is 5.
The charge of the molecule is -2.