Question

Explain the following.

₁₃Al is a metal, ₁₄Si is a metalloid and ₁₅P is a nonmetal.

Answer 1

1. Electronic configuration of Al is [Ne] 3s² 3p¹, ₁₄Si is [Ne] 3s² 3p² and that of ₁₅P is [Ne] 3s² 3p³.
2. Metals are characterized by the ability to form compounds by loss of valence electrons.
3. ‘Al’ has 3 valence electrons, thus shows a tendency to lose 3 valence electrons to complete its octet. Hence, Al is a metal.
4. Nonmetals are characterized by the ability to form compounds by a gain of valence electrons in the valence shell.
5. ‘P’ has 5 valence electrons thus, shows a tendency to gain 3 electrons to complete its octet. Hence, ‘P’ is a nonmetal.
6. Si has four valence electrons, thus it can either lose/gain electrons to complete its octet. Hence, behaves as a metalloid.