Bromine is unique among the elements in that it is the only non-metal that is a liquid at room temperature. This property can be attributed to its molecular structure and the nature of its intermolecular forces.
Bromine exists as diatomic molecules (Br2) in its natural state. The molecules are held together by Van der Waals forces, which are relatively weak compared to covalent bonds but stronger than the forces in gases.
At room temperature (about 20°C or 68°F), bromine’s molecular weight and the presence of these intermolecular forces allow it to condense into a liquid. In contrast, lighter non-metals like chlorine and fluorine exist as gases at this temperature due to their smaller molecular sizes and weaker intermolecular forces.
In summary, bromine’s status as a liquid at room temperature results from its heavier molecular weight and stronger Van der Waals forces, which enable it to remain in a liquid state under standard conditions.