Here's why:
* Gases have particles that are widely spaced and move randomly. They have no fixed shape or volume.
* Liquids have particles that are closer together than gases, but still have some freedom of movement. They have a fixed volume but not a fixed shape.
* Solids have particles that are tightly packed and arranged in a regular, repeating pattern. They have a fixed shape and volume.
Since the description matches the characteristics of a gas, we can conclude that bromine is in the gaseous state when its particles are far apart and random.
