Question

differentiate between mercury and bromine

Answer 1

Mercury has a special electron configuration that means the bondsbetween the mercury atoms are much weaker than the bonds of other metals, so it's liquid at room temperature instead of solid. Bromine just happens to have a boiling point above room temperature - it's not unusual for its group, or anything.

Answer 2

Mercury- a metal liquid at room temperature

Bromine- a non metal liquid at room temperature