Final answer:
One formula unit of Ba₃(PO₄)₂ consists of 3 barium ions (Ba²⁺), 2 phosphate ions (PO₄³⁻), 2 phosphorus atoms, and 8 oxygen atoms.
Step-by-step explanation:
To determine the number of atoms and ions in one formula unit of Ba₃(PO₄)₂, we need to look at the components of this compound. Barium is the cation (Ba²⁺), and phosphate is the polyatomic anion (PO₄³⁻). The subscript outside the parentheses for the phosphate ion (₄) indicates that there are four oxygen atoms bonded to one phosphorus atom within this group.
The subscript '3' after the barium (Ba) indicates that there are three barium atoms. Similarly, the subscript '2' after the phosphate group (PO₄) means there are two phosphate groups in the compound. Within each phosphate group, there is one phosphorus atom and four oxygen atoms. Therefore, in one formula unit of Ba₃(PO₄)₂, there are a total of 3 barium atoms, 2 phosphorus atoms, and 8 oxygen atoms.
Calculating the total, we have:
- 3 Barium ions (Ba²⁺).
- 2 Phosphate ions (PO₄³⁻), each consisting of 1 phosphorus atom and 4 oxygen atoms, hence 2x1=2 phosphorus atoms and 2x4=8 oxygen atoms.
So, one formula unit of Ba₃(PO₄)₂ has a total of
3 barium ions, 2 phosphate ions, 2 phosphorus atoms, and 8 oxygen atoms.