Chapter U1.19, Problem 12E

Interpretation Introduction

Interpretation:

The reason for the chlorine to not become an argon atom after the addition of 1 electron to it needs to be explained.

Concept introduction:

The addition of an electron to an atom results in the formation of ion with negative charge.

Answer to Problem 12E

The chloride ion doesn’t become an argon atom on addition of an electron to chlorine because the electronic configuration is same but the number of protons are different so atomic number is still 17.

Explanation of Solution

$\begin{array}{l}Cl{\text{ + e}}^{-}\to C{l}^{-}\\ 17p^{+}17p^{+}\\ 17e^{-}18e^{-}\\ Ar\left(18p^{+},18e^{-}\right)\end{array}$

As consider the above equation the chlorine ion gain an electron to become a chloride ion and it gets negative charge this chloride ion have the 17 protons and 18 electrons. This atomic configuration is not equal to argon configuration because it has the 18 protons and 18 electrons.

Conclusion

The chlorine does not become argon because number of protons or atomic number does not change after addition of an electron.