Answer:
A
Explanation:
Recall that a mole of any substance contains 6.02 × 10²³ amounts of that substance.
In other words, a mole of gold atoms contains 6.02 × 10²³ gold atoms.
Hence, by dimensional analysis, we have that:
[tex]\displaystyle 4.81\times 10^{21} \text{ Au} \cdot \frac{1\text{ mol Au}}{6.02\times 10^{23} \text{ Au}} = 7.99\times 10^{-3} \text{ mol Au}[/tex]
Therefore, there is about 7.99 × 10⁻³ moles of gold present in the sample.
In conclusion, the answer is A.
