Question

A textbook says that each ion in an ionic compound has the noble gas configuration. What about aluminium oxide?

Answer 1

yes.

Al has lost its three outside electrons, oxygen has gained two electrons. Now the outside shell of Al has 8 (it was 2,8,3) and oxygen has 8 (it was 2,6). The Al now has a +3 charge (having lost 3 electrons) and the oxygen has a charge of -2 since it gained two electrons.