# 26.8 moles of argon contain how many atoms?

$26.8 \times {N}_{A}$, where ${N}_{A} = \text{Avogadro's Number}$.
${N}_{A} = \text{Avogadro's Number} = 6.022 \times {10}^{23} \cdot m o {l}^{-} 1$.
Thus, $\text{number of Ar atoms}$ $=$ $6.022 \times {10}^{23} \cdot \cancel{m o {l}^{-} 1} \times 26.8 \cancel{m o l}$ $=$ ??