Question

How many moles are 1.20 x10^25 atoms of phosphorus?

Answer 1

1 mole of any substance contain Avogadro's number of molecules so we can calculate the number of moles by dividing the provided number of atoms over Avogadro's number to obtain the number of moles 

Answer : 19.9 moles of phosphorus

  Solution : Atoms / Avogadro's number (6.022 x 10²³ atoms/mol)

 1.20 x 10²⁵ atoms / 6.022 x 10²³ = 19.927

Answer 2

Answer:

There are 19.9 moles of phosphorus in $1.20*10^{25}$ atoms of phosphorus

Explanation:

According to Avogadro´s number, 1 mol of each element has $6.022*10^{23}$ atoms of the same element, so:

1 mol of phosphorus = 6.022$*10^{23}$ moles of phosphorus.

As we have $1.20*10^{25}$ moles of phosphorus, we need to find the relationship between this quantity of moles and the number of atoms using the Avogadro´s number:

$1.20*10^{25}$ atoms of phosphorus * $\frac{1}{6.022*10^{23}}\frac{moles of phosphorus}{atoms of phosphorus}$ = 19.9 moles of phosphorus