The table below shows information about three isotopes of silicon.
Mass numberPercentage abundance (%)2892.22294.69303.09\begin{array}{c|c} \text{Mass number} & \text{Percentage abundance (\%)} \\ \hline 28 & 92.22 \\ 29 & 4.69 \\ 30 & 3.09 \\ \end{array}Mass number282930Percentage abundance (%)92.224.693.09Calculate the relative atomic mass (ArA_rAr) of silicon.
Give your answer to 3 significant figures.
41 exam-style questions on AQA GCSE Chemistry 1.1 A simple model of the atom, symbols, relative atomic mass, electronic charge and isotopes, covering 1.1.1 Atoms, elements and compounds, 1.1.2 Mixtures, 1.1.3 The development of the model of the atom (common content with physics), 1.1.4 Relative electrical charges of subatomic particles, 1.1.5 Size and mass of atoms, 1.1.6 Relative atomic mass, and 1.1.7 Electronic structure. Each one has a worked solution and a mark scheme showing where the marks go.