Relative Atomic Mass (AQA GCSE Chemistry Combined Science): Quizzes

$1/12$th the mass of a carbon-12 atom

The abundance of each isotope

A weighted average

$Ar$ is weighted; mass number is one isotope

$\frac{\sum(\text{isotope mass} \times \text{abundance})}{\text{total abundance}}$

$35.5$

$75\%$

Different isotopes contribute to it

On the periodic table

$\text{Moles} = \frac{\text{Mass}}{Ar \text{ or } Mr}$