How many moles are in 7.12 x 1021 atoms of iron?

0.0118mol

Explanation:

To obtain the number of moles (n) in the given number of molecules of iron, we divide by Avagadro's number (6.02 × 10²³).

That is; n = number of molecules ÷ nA

According to this question, there are 7.12 x 1021 atoms of Iron (Fe).

n = 7.12 x 10²¹ ÷ 6.02 × 10²³

n = 7.12/6.02 × 10^ (21 - 23)

n = 1.183 × 10^-2

n = 0.0118mol