Why are covalent compound volatile sublime?

Answer 1

There are some covalent compounds that are volatile and undergo sublimation such as iodine. Although, covalent compounds aren't always volatile. For example, diamond, the hardest solid known, does not change its phase even in a higher temperature around 3000 K.

Answer 2

Covalent compounds have weaker intermolecular forces compared to ionic compounds, allowing them to more easily break apart and transition into the gas phase through sublimation. This is why some covalent compounds can be volatile and sublime at lower temperatures.