Chapter 6, Problem 65A

Interpretation Introduction

Interpretation:

The octet rule needs to be explained and the reason for hydrogen and helium to be exception to the octet rule needs to be explained.

Concept introduction:

Every element tends to have eight electrons in its valence shell. This tendency of having eight electrons in the valence shell is termed as the octet rule. There are certain exceptions of this rule like H and He which does not require eight electrons to meet the octet rule.

Answer to Problem 65A

H and He are exception to the octet rule because they need only two electrons to fulfill the octet.

Explanation of Solution

According to octet rule every element tend to obtain a valence shell configuration with a total of eight electrons. An element obtain octet by either gaining or losing electrons.

Number of electrons in H is one and number of electrons in He is two. Therefore, H and He has only one s orbital. So, both H and He are considered to be exception to the octet rule.

Conclusion

H and He are exception to the octet rule since they contain only an s orbital. H and He needs only two electrons to fill the valence shell.