Here's how to determine the number of bromine molecules in the flask:

1. Avogadro's Number

Avogadro's number tells us the number of particles (atoms, molecules, ions, etc.) in one mole of a substance. It's approximately:

* 6.022 x 10²³ particles/mol

2. Calculation

* Start with the moles of bromine: 0.380 mol Br₂

* Multiply by Avogadro's number: 0.380 mol Br₂ * (6.022 x 10²³ molecules Br₂ / 1 mol Br₂)

Result:

The flask contains approximately 2.29 x 10²³ bromine molecules.