Answer:
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