Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Relative atomic mass
19 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
2 marks · Hard
Answer and see the solution →A sample of element Q contains 10% of isotope Q-40 and 90% of isotope Q-42.
Calculate the relative atomic mass of Q. Give your answer to one decimal place.
Question 2
5 marks · Hard
Answer and see the solution →(a)[1 mark]Describe what isotopes are.
(b)[3 marks]The element magnesium has isotopes with mass numbers 24, 25, and 26. Give the number of protons and neutrons in each of these isotopes.
Isotope Number of protons Number of neutrons ^24Mg ^25Mg ^26Mg (c)[1 mark]Explain why magnesium-24, magnesium-25, and magnesium-26 all have the same chemical properties.
Question 3
2 marks · Hard
Answer and see the solution →The element X has two stable isotopes: X-64 (mass = 64, abundance = 73%) and X-66 (mass = 66, abundance = 27%).
Calculate the relative atomic mass of X. Give your answer to one decimal place.