Question

Question #45a3b

Answer 1

The molecule `Al(PO_4)_3` contains the elements Aluminum, Phosphorus and Oxygen.

For this molecule the Aluminum has one (1) atom.
The Phosphate ion `(PO_4)` has three units which means the subscript 3 outside of the parenthesis gets distributed to each value inside thus there are three (3) Phosphorus atoms and twelve (12) Oxygen atoms.

Al = 1
P = 3
O = 16

This means that the molecule `Al(PO_4)_3` contains a total of 16 atoms (1 +3+12 = 16).

Technically however, there is no molecule of `Al(PO_4)_3` since Aluminum has an ionic charge of +3, `Al^+3` and Phosphate has a charge of -3, `PO_4^-3`. This means that the actual molecule is `AlPO_4`.

Therefore the atom count is

Al = 1
P = 1
O = 4

For a total of 6 atoms in the molecule.