Question

Zn (30): $1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{10}}4{{s}^{2}}$
How to find the valency of the zinc by electronic configuration?

Answer 1

Hint: The combining capacity of an atom with other atoms is called its valence. At the time of combining with other atoms some atoms will lose their valence electrons. If the atom loses its valence electrons then it will get a positive charge on it.

Complete answer:
- In the question it is given to find the valence of the zinc.
- Zinc is an element belonging to d-block.
- The atomic number of the zinc is 30, means zinc contains 30 electrons in its electronic configuration.
- The electronic configuration of zinc is as follows.
\[1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{10}}4{{s}^{2}}\]
- From the above electronic configuration we can say that in orbital-1 there are 2 electrons, in orbital-2 there are 8 electrons (2s and 2p), in orbital three there are 18 electrons (3s, 3p and 3d) and in orbital-4 there are only 2 electrons (4s).
- We can say that the 3d orbital is fully filled with ten electrons means they are inert and cannot be considered as valence electrons because they cannot be involved in the bonding formation.
- So, there are only two electrons present in the 4s orbital acts as valence electrons, nothing but involved at the time of formation of bond with other atoms.

- Therefore the number of valence electrons in a zinc atom is two.

Note: All the atoms won’t have the same valence. The valence of an atom is going to depend on the capability of losing electrons at the time of bond formation with the other atoms. Due to the presence of valence electrons, atoms react very easily and form molecules.