1 Answer

0.36 moles

Step-by-step explanation:

To find the number of moles in a substance given it's number of entities we use the formula

$n = (N)/(L) \\$

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

$n = \frac{2.17 * {10}^(23) }{6.02 * {10}^(23) } = (2.17)/(6.02) \\ = 0.360465...$

We have the final answer as

Hope this helps you