Question

Is aluminium oxide a metal or nonmetal?

Answer 1

Hint : Aluminium oxide is also commonly known as alumina and it is used to extract pure aluminium. Alumina is obtained mainly from bauxite and has a chemical formula $A{{l}_{2}}{{O}_{3}}$ . Aluminium and oxygen behave differently when they are alone and they behave differently when they form alumina.

Complete Step By Step Answer:
The correct answer to this question is that aluminium oxide is not a metal, it is a non-metal.
Aluminium oxide has a chemical formula $A{{l}_{2}}{{O}_{3}}$ , it is also more commonly known as alumina. Alumina is used to obtain pure aluminium and it is obtained from the bauxite ore.
Aluminium oxide has a similar aspect as sodium chloride has. Sodium and chlorine are two very distinct elements, sodium cannot be kept open in air as it will catch fire and chlorine gas is poisonous. But, when they both combine they form something which could be eaten and is a necessary part of our diet.
Aluminium oxide behaves in a similar way, aluminium is highly metallic and is used in many metal related application, but when it combines with oxygen to form aluminium oxide ( $A{{l}_{2}}{{O}_{3}}$ ), it loses its metallic character completely. Thus, aluminium oxide is a non-metal. Aluminium oxide rather has properties and characteristics which we list under ceramics.
And this is the reason that oxidized aluminium does not fit into the category of a metal.

Note :
When aluminium combines with oxygen to form aluminium oxide or alumina, the bond between them is immensely strong. Thus, the process of getting aluminium from alumina is very hard. It requires a lot of energy to produce aluminium from alumina.