Understanding the Concepts

* Mole (mol): A unit of measurement for the amount of a substance. One mole contains 6.022 x 10²³ particles (atoms, molecules, etc.). This number is known as Avogadro's number.

Calculation

1. Bromine (Br₂) is a diatomic molecule: This means each molecule of bromine contains two bromine atoms.

2. Use Avogadro's number: To find the number of molecules, multiply the number of moles by Avogadro's number:

* 0.100 mol Br₂ * (6.022 x 10²³ molecules/mol) = 6.022 x 10²² bromine molecules

Therefore, a flask containing 0.100 mol of liquid bromine contains 6.022 x 10²² bromine molecules.