Chapter 6, Problem 69A

Interpretation Introduction

Interpretation:

Whether chlorine atom has changed to argon atom on gaining an electron or not needs to be explained.

Concept introduction:

Electronic configuration of an element is the arrangement of elements in different orbitals like s, p, d, f. The filing of the electrons in the orbitals follow the Aufbau Principle.

Answer to Problem 69A

Chlorine atom does not change to argon atom on gaining an electron. It is because although they have same electronic configuration, they have different atomic numbers.

Explanation of Solution

Chlorine has the electronic configuration 1s²2s² 2p⁶ 3s²3p⁵or [Ne] 3s²3p⁵. On gaining one electron, Chlorine becomes Chloride ion (Cl^-). The Chloride ion has 18 electrons and hence, it has the similar electronic configuration as that of the element Argon, i.e., ([Ne] 3s² 3p⁶). But since, both the elements Argon and Chloride has different atomic numbers, therefore they are different elements irrespective of the fact that they have the same electronic configuration.

Conclusion

On gaining an electron, Chlorine becomes Chloride ion. The electronic configuration of the Chloride ion and that of the Argon is same. But, , since both the elements have different atomic numbers, therefore, they are different elements.