A mass spectrometer is used to determine the relative abundances of the isotopes in a sample of neon. The results are shown in the table below.
Relative isotopic massPercentage abundance (%)19.99290.4820.9940.2721.9919.25 \begin{array}{c|c} \text{Relative isotopic mass} & \text{Percentage abundance (\%)} \\ \hline 19.992 & 90.48 \\ 20.994 & 0.27 \\ 21.991 & 9.25 \\ \end{array} Relative isotopic mass19.99220.99421.991Percentage abundance (%)90.480.279.25Calculate the relative atomic mass (ArA_rAr) of this sample of neon.
Give your answer to 4 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.