Silica (SiO₂) is not a gas at room temperature and pressure. It is actually a solid in its most common form, quartz.

Here's why:

* Strong Bonding: Silica has strong covalent bonds between silicon and oxygen atoms, creating a rigid, crystalline structure.

* High Melting Point: This strong bonding results in a high melting point (around 1713°C), meaning it requires a significant amount of energy to break the bonds and transform it into a liquid, let alone a gas.

* High Boiling Point: Similarly, silica has an extremely high boiling point, over 2230°C.

* Sublimation: While silica doesn't readily exist as a gas, it can undergo sublimation, meaning it transitions directly from a solid to a gas under extremely high temperatures.

So, while silica can exist in a gaseous form at incredibly high temperatures, it's definitely not a gas at normal conditions.