Relative atomic mass (Edexcel GCSE Chemistry Combined Science): Flashcards

Relative atomic mass

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

The abundance of each isotope of the element

Weighted average of all isotopes

No, mass number refers to just one isotope

$\frac{(\text{mass} \times \text{abund}) + ...}{\text{total abund}}$

Chlorine-35 and Chlorine-37

Approximately 75%

35.5

On the periodic table

Different isotopes contribute to its value

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