Final answer:
There are a total of 32 electrons in the Lewis structure of the phosphate ion PO4³⁻, reflecting contributions from the central phosphorus atom, the four oxygen atoms, and the additional electrons due to the ion's charge.
Step-by-step explanation:
The Lewis structure of the phosphate ion PO4³⁻ includes a total of 32 electrons. In the phosphate ion, the central phosphorus atom is surrounded by four oxygen atoms. The phosphorus atom has five valence electrons, and each oxygen atom has six valence electrons, leading to a total of 5 + (4 × 6) = 29 electrons. Considering the ion has a -3 charge, we add an additional three electrons to account for the negative charge, resulting in 32 electrons in the Lewis structure of the phosphate ion. These electrons are distributed to fulfill the octet rule for each oxygen and expand the octet for phosphorus, which is in the third period of the periodic table and capable of such expansion.