Here's why:

* Bromine is a halogen: It's in the same group as fluorine, chlorine, and iodine on the periodic table.

* Halogens have increasing melting and boiling points as you go down the group: This is because the atoms get larger and have more electrons, leading to stronger intermolecular forces.

* Bromine is in the middle: It's heavier than chlorine (a gas at room temperature) but lighter than iodine (a solid at room temperature).

Therefore, bromine exists as a liquid at typical room temperatures.