Question

How does the following property vary on moving down the group 16?

Catenation

Answer 1

1. Oxygen shows very little tendency towards catenation, forming mainly simple peroxides like \[\ce{H - O - O - H}\].
2. Sulphur exhibits a strong tendency to catenate, forming long chains and rings like S₈.
3. Selenium and tellurium also show catenation but less prominently than sulphur.
4. The propensity for catenation decreases as we move further down from sulphur to polonium.
5. This decline is due to the increase in atomic size and weaker \[\ce{M - M}\] bonds in heavier elements.

Thus, catenation tendency increases from oxygen to sulphur, then decreases down the group from sulphur to polonium.