Question #45a3b

1 Answer
Dec 17, 2014

The molecule Al(PO4)3 contains the elements Aluminum, Phosphorus and Oxygen.

For this molecule the Aluminum has one (1) atom.
The Phosphate ion (PO4) 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(PO4)3 contains a total of 16 atoms (1 +3+12 = 16).

Technically however, there is no molecule of Al(PO4)3 since Aluminum has an ionic charge of +3, Al+3 and Phosphate has a charge of -3, PO34. This means that the actual molecule is AlPO4.

Therefore the atom count is

Al = 1
P = 1
O = 4

For a total of 6 atoms in the molecule.