Condensation occurs through the release of energy
Well, if you look at group 1 of the periodic table, you will notice a thrend. All elements in group 1 have 1 valence / outer electron. Then you look at period 2, 3, 4 and so on, you will see that the group number corresponds the number of valence/ outershell electrons. Hence, the group determines the electron(s) on the outershell.
Answer:
Decomposition of aluminium oxide forms aluminium atoms and oxygen atoms.
Explanation:
<u>Decomposition reaction:</u>
When a single compound break down into two or more simpler products.
For example "AB" reactant undergoes decomposition to form "A" and "B" products.
The chemical reaction is as follows.

The given compound is aluminium oxide.
The decomposition reaction of aluminium oxide is a follows.

The balanced equation is as follows.

Therefore, Decomposition of aluminium oxide forms aluminium atoms and oxygen atoms.