The total number of valence electrons in the phosphate ion is

32

Step-by-step explanation:

There are two ways you can count the valence electrons.

A. From the Periodic Table

1 * P (Group 15) = 5

4 * O (Group 16) = 4 * 6 = 24

+3 e⁻ (for the charges) = 3

Total = 32

B. From the Lewis structure

In the Lewis structure (below), each line (bond) represents a pair of bonding electrons, and each dot represents an unbound electron (half a lone pair).

5 lines (bonds) = 5 * 2 = 10

3 single-bonded O atoms = 3 * 6 = 18

1 double-bonded O atom = 4

Total = 32