Question

(b) what number, in addition to the answer to part (a), is needed to determine the number of atoms of ca in the sample?
note: cabr₂
1 mol cabr₂ = 2 mol br
1 mol cabr₂ = 1 mol ca

Explanation:

To find the number of Ca atoms, we need the number of moles of \( \text{CaBr}_2 \) (from part a) and Avogadro's number (\( 6.022 \times 10^{23} \) atoms/mol) to convert moles of Ca (equal to moles of \( \text{CaBr}_2 \)) to atoms. So Avogadro's number is needed.

Answer:

Avogadro's number (or \( 6.022 \times 10^{23} \) atoms/mol)