Chapter 8, Problem 44A

Interpretation Introduction

Interpretation: The reason for neon to be monatomic but chlorine to be diatomic needs to be explained.

Concept Introduction: Elements can exist as molecules or individual atoms depending on the number of valence electrons present in the atom of the element. If sharing of electron pairs is required, atoms of the element are present in combined form as molecules in the atmosphere. For atoms with a complete octet, they are present as individual atoms.

Explanation of Solution

Neon is found as an individual atom in the Earth’s atmosphere. The number of valence electrons in a neon atom is 8 thus, it has a complete octet. It does not bond with any other atom to complete its octet. Therefore, neon is monatomic. On the other hand, chlorine has 7 valence electrons. It requires one electron to complete its octet. It can gain 1 electron from any other atom or it can also share one electron with another chlorine atom to form Cl-Cl covalent bond. Thus, chlorine is diatomic.