A chemist uses a mass spectrometer to find the isotopes present in samples of some elements.
The mass spectrometer shows that a sample of silver contains silver-107 and silver-109 in the ratio 26:2426:2426:24. Calculate the relative atomic mass of silver. Give your answer to one decimal place.
Gallium is used in blue LEDs. Gallium has two isotopes, gallium-69 and gallium-71. The relative atomic mass of gallium is 69.7. Calculate the percentage abundance of each isotope.
Element Z has two isotopes. Their mass numbers differ by 1. The lighter isotope has an abundance of 20.0%. The relative atomic mass of Z is 10.8. Deduce the mass numbers of the two isotopes and identify element Z.
Suggest why samples of the same element from different places on Earth can have slightly different relative atomic masses.
46 exam-style questions on Edexcel GCSE Chemistry 2.1 Atomic structure, covering 2.1.1 Development of the atomic model, 2.1.2 Structure of the atom and subatomic particles, 2.1.3 Mass number, isotopes and relative atomic mass, and 2.1.4 Calculating relative atomic mass from isotopic abundance. Each one has a worked solution and a mark scheme showing where the marks go.