B) Al2O3
Aluminium reacts with oxygen to form aluminium oxide.
The chemical reaction for the reaction between Aluminium and Oxygen is;
4Al+ 3O₂→ 2Al₂O₃
Therefore;
Compound X is Aluminium oxide (Al₂O₃)
i just got this problem. it's 90.3
a:
by the combination of an unlimited number of elements