Sodium bromide (NaBr) is not a gas under standard conditions. It's a white, crystalline solid.

Here's why:

* Ionic Compounds: Sodium bromide is an ionic compound, formed by the electrostatic attraction between positively charged sodium ions (Na+) and negatively charged bromide ions (Br-).

* Strong Bonds: The ionic bonds in sodium bromide are very strong, requiring a lot of energy to break them.

* High Melting Point: This strong bonding results in a high melting point for sodium bromide (747 °C or 1377 °F), far above room temperature.

Therefore, sodium bromide does not exist as a gas under normal conditions.