Question

How many atoms are there in 5 moles of phosphorus

Answer 1

Given:

$n=5\:\rm mol$

The amount of moles is given by

$$n=\frac{N}{N_A}$$

Hence, the number of atoms is

$$N=nN_A\\ =5\:\rm mol*6.02*10^{23}\: mol^{-1}=3.01*10^{24}$$