# How many atoms are in 3.5 moles of arsenic?

Jul 11, 2018

One mole of stuff contains ${N}_{A}$ individual items of stuff...where ${N}_{A} = 6.022 \times {10}^{23} \cdot m o {l}^{-} 1$...
And so we take the product, $3.5 \cdot m o l \times 6.022 \times {10}^{23} \cdot m o {l}^{-} 1 = 2.11 \times {10}^{24} \cdot \text{individual arsenic atoms} \ldots$
Please note that here we gots $3.5 \cdot m o l$ of arsenic ATOMS, a mass of $262.1 \cdot g$. White arsenic (which is rather nasty stuff!) is the $A {s}_{4}$ molecule.