* 1 mol Br2 represents one mole of bromine molecules (Br2).

* Avogadro's number tells us that there are 6.022 x 10^23 molecules in one mole of any substance.

* Each Br2 molecule contains two bromine atoms.

Therefore, the number of bromine atoms in 1 mol Br2 is:

* (1 mol Br2) * (6.022 x 10^23 molecules/mol) * (2 atoms/molecule) = 1.2044 x 10^24 bromine atoms

In short, the number of bromine atoms in 1 mol Br2 is twice Avogadro's number.