Answer:
The answer is option A
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\ [/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{18.0 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{18}{6.02} \\ = 2.99003322...[/tex]
We have the final answer as
2.99 moles
Hope this helps you
