Question

How many grams are in 2.94 x 1017 atoms of hafnium?

Answer 1

`8.71 * 10^(-5)\text{g}`

Step-by-step explanation:

We can convert
`2.94*10^(17) \text{ atoms}` of Hafnium to grams using unit conversion (also called dimensional analysis).

We know the following conversion ratios:

•
`\frac{1\text{ mole}}{6.022* 10^(23) \text{ atoms}}` (Avogadro's Number)

•
`\frac{178.49 \text{g}}{1\text{ mole}}` (Atomic Mass of Hafnium)

Now, we can multiply these by the given quantity of atoms:

`\frac{2.94*10^(17) \text{ atoms}}{1}*\frac{1\text{ mole}}{6.022* 10^(23) \text{ atoms}}*\frac{178.49 \text{g}}{1\text{ mole}} = \boxed{8.71 * 10^(-5)\text{g}}`

So,
`2.94*10^(17) \text{ atoms}` of Hafnium are approximately 0.0000871 grams.