Question

write the electronic configuration of aluminium and oxygen​

Answer 1

Answer:

Three Oxygen atoms gains two electrons each ( total of six) from two Al atoms, each Al atom loses three electrons (total of six) to three oxygen atom , in this process each Al atom becomes Al3+ ion and Oxygen atom after gaining two electrons becomes O2− ion. or the formula is Al2O3 .

Explanation:

Answer 2

Valency of an atom is the number of electrons that are required to be added or removed from the outermost shell of an atom to complete its octate.

Alumunium has an atomic number (Z) of 13

So, its electronic configuration is [Ne] 3s^2 3p^1

Hence, it needs to lose 3 electrons to attain stable configuration, hence its valency is three.

Oxygen has an atomic number (Z) of 18

So, its electronic configuration is [He]2s^23p^1 .

therefore, it needs to gain more electrons to attain stable ocate. Hence, its valency is 2