Question

What is the electron arrangement of an Al³+ ion?

A. 2,8
B. 2,3
C. 2, 8, 3
D. 2, 8, 8

Answer 1

Correct option is A)

The arrangement of electrons in different energy levels around a nucleus is called electronic configuration. The periodicity in properties of elements in any group is due to repetition in the same valence shell electronic configuration after a certain gap of atomic numbers such as 2, 8, 8, 18, 18, 32.

The atomic number of Al is 13 and its electronic configuration is 2, 8, 3. So, the electronic configuration of
`\text{Al}^3+` is 2,8.