Answer
C
Work Step by Step
$8000\ atoms\ of\ Al\times\frac{3\ molecules\ of\ Br_2}{2\ atoms\ of\ Al}=12,000\ molecules\ of\ Br_2$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.