# What is the mass of one mole of beryllium if the atomic mass of beryllium is 9.01?

$9.01 \text{ g}$.
Example 1: Water ($\text{H"_2"O}$) has two hydrogen atoms and one oxygen atom per molecule. The two hydrogen atoms each have an atomic mass of $1.008$, the oxygen atom has an atomic mass of $15.999$, the sum for all three atoms is $18.015$. So a mole of water molecules has a mass of $18.015 \text{ g}$.
Example 2: Beryllium has an aromuc mass of $9.01$. So a mole of beryllium atoms has a mass of 9. 01" g".