Question

Why do noble gases exist as monoatomic molecules?

Answer 1

1. Noble gases have a completely filled outer electron shell, making them very stable and chemically inert.
2. They have no tendency to share or gain electrons, so they do not form bonds with other atoms.
3. They exist as single atoms (monoatomic) because weak van der Waals forces are the only interactions between them.
4. Their monoatomic nature is confirmed by physical properties like specific heat ratios matching monoatomic gases.

Hence, noble gases remain as isolated atoms rather than forming molecules.