# What is a "mole"?

Mar 17, 2016

#### Answer:

One mole of stuff contains $6.022140857 \left(74\right) \times {10}^{23}$ individual items of that stuff.

#### Explanation:

$6.022140857 \left(74\right) \times {10}^{23}$ is often abbreviated as ${N}_{A}$; it is simply a number, like 10, or a dozen, or a Bakers' dozen. It has the property that if there are ${N}_{A}$ ""^12C atoms, then there is a mass of $12.00$ $g$ precisely of ""^12C. So, if have a mole of methane, $C {H}_{4}$, I have a mass of $16.00$ $g$. In terms of ${N}_{A}$, how many (i) carbon atoms, and (ii) hydrogen atoms are present in $16.00$ $g$ of methane.