# Question #b1f48

Apr 11, 2015

Very easy. If you have a given mass here is how you calculate the number of atoms:

$n = \frac{m}{M}$

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

$m$ - mass (g)
$M$ - molar mass (g/(mole)
$n$ - amount of substance (mole)
$N$ - number (of atoms for example)
$L$ - Avogadro's number $6.022 \times {10}^{23}$