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Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section

Relative atomic mass

19 practice questions

Start practising (8 questions)

Practice questions

1–8 of 8 · Normal

  1. Question 1

    2 marks · Normal

    State the number of protons and the number of neutrons in an atom of magnesium-25 ().

    Answer and see the solution →

  2. Question 2

    4 marks · Normal

    Use the information below to answer the questions about isotopes.

    (a)

    Give the definition of isotopes.

    [1 mark]
    (b)

    State one similarity and one difference between the isotopes and .

    [2 marks]
    (c)

    Explain why the chemical properties of the two isotopes are the same.

    [1 mark]
    Answer and see the solution →

  3. Question 3

    3 marks · Normal

    Bromine consists of two isotopes: and . The percentage abundances are 51% and 49% respectively. Calculate the relative atomic mass of bromine. Give your answer to 1 decimal place.

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  4. Question 4

    3 marks · Normal

    Chlorine exists mainly as two isotopes, and . The Periodic Table gives chlorine a relative atomic mass of 35.5.

    Explain why this value is not a whole number. Your answer should refer to isotopes and how the value is calculated.

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  5. Question 5

    4 marks · Normal

    The table shows the abundances of three isotopes of element X.

    IsotopeRelative Mass% Abundance
    X-101020
    X-111150
    X-121230
    Answer and see the solution →

  6. Question 6

    1 mark · Normal

    Which statement correctly describes all isotopes of an element?

    1. A.They have the same mass number but different atomic numbers.
    2. B.They have the same number of protons but different numbers of neutrons.
    3. C.They have different chemical properties.
    4. D.They contain the same number of neutrons.
    Answer and check →

  7. Question 7

    2 marks · Normal

    An atom of sodium-23 () has how many neutrons?

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  8. Question 8

    4 marks · Normal

    Consider two isotopes of carbon: and .

    (a)

    State the number of protons and neutrons in .

    [1 mark]
    (b)

    State the number of protons and neutrons in .

    [1 mark]
    (c)

    Explain why and are considered isotopes of the same element.

    [1 mark]
    (d)

    Describe one way in which the two isotopes differ.

    [1 mark]
    Answer and see the solution →