Here's why:

* Location on the Periodic Table: Bromine is located in Group 17 (also known as the halogens) on the periodic table, which is a group of nonmetals.

* Physical Properties: Bromine exists as a reddish-brown liquid at room temperature, which is a characteristic of nonmetals.

* Chemical Properties: Bromine is highly reactive and forms compounds readily, another characteristic of nonmetals.

Let me know if you have any more questions!