Here's why:

* Nonmetals: Bromine is a nonmetal. Nonmetals are generally poor conductors of heat because their atoms are tightly bound together and don't have free electrons that can easily carry thermal energy.

* Liquid at Room Temperature: Bromine is a liquid at room temperature. Liquids are generally less efficient conductors of heat than solids because their molecules are less tightly packed and can move around more freely.

Examples of other poor conductors of heat:

* Other Nonmetals: Sulfur, phosphorus, iodine, chlorine.

* Insulators: Many materials used as insulators, like wood, plastic, and rubber, are also poor conductors of heat.

Good Conductors of Heat:

* Metals: Metals are excellent conductors of heat because they have free electrons that can easily move and transfer thermal energy. Examples include copper, aluminum, and iron.