Chapter U1.19, Problem 9E

Interpretation Introduction

Interpretation:

Four ions must be listed which have same number of electrons as present in Ar.

Concept introduction:

Noble gases have very stable electronic configuration with complete octets. Some of the noble gases are He, Ne, Ar, Kr, Xe and Rn.

Argon is an inert gas with 18 electrons.

Answer to Problem 9E

Four ions with same number of electrons as present in Ar are K ⁺ , Ca + 2, S² - and P^3-.

Explanation of Solution

The atomic number of Ar is 18 thusm ions must have 18 electrons. K, Ca, S and P have 19, 20, 16 and 15 electrons respectively. To make 18 electrons in these 1 and 2 electrons must be removed from K and Ca atoms respectively. Similarly, 2 and 3 electrons must be added to S and P atoms respectively. This results in the formation of K ⁺ , Ca + 2, S² - and P³ - ions.

Conclusion

Thus, the required ions are K ⁺ , Ca + 2, S² - and P³ - which have same (18) electrons as present in Ar.