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

Atomic Structure

108 practice questions

Topics covered

Practice questions

1–10 of 108

  1. Question 1

    1 mark · Easy

    State the meaning of the term "atom".

    Answer and see the solution →
  2. Question 2

    3 marks · Easy

    Answer the following about atoms and molecules.

    (a)

    Define a molecule.

    [1 mark]
    (b)

    Give an example of a molecule formed from atoms of two different elements.

    [1 mark]
    (c)

    Explain why atoms of helium (He) are not classed as molecules.

    [1 mark]
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  3. Question 3

    2 marks · Easy

    A molecule of methane (CH₄) contains one carbon atom and four hydrogen atoms. Calculate the total number of atoms present in three molecules of methane. Show your working.

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  4. Question 4

    2 marks · Easy

    Explain the difference between an atom of oxygen (O) and a molecule of oxygen (O₂).

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  5. Question 5

    3 marks · Easy

    The table shows three simple substances. Use the information to answer the questions.

    Atoms in substances
    SubstanceAtoms present
    HydrogenH₂
    NitrogenN₂
    WaterH₂O
    (a)

    Which of these substances are molecules made from only one type of atom?

    [1 mark]
    (b)

    How many atoms are present in one molecule of water?

    [1 mark]
    (c)

    State why water is classified as a molecule.

    [1 mark]
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  6. Question 6

    1 mark · Easy

    Complete the sentence: A molecule must contain

    atom(s).

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  7. Question 7

    3 marks · Easy

    This question is about atoms and molecules.

    (a)

    State what an atom is.

    [1 mark]
    (b)

    State what a molecule is.

    [1 mark]
    (c)

    Describe one feature that atoms and molecules have in common.

    [1 mark]
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  8. Question 8

    2 marks · Easy

    Each molecule of carbon dioxide (CO₂) contains one carbon atom and two oxygen atoms. How many atoms are present in four molecules of carbon dioxide? Show your working.

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  9. Question 9

    3 marks · Normal

    A molecule of ammonia (NH₃) contains both nitrogen and hydrogen atoms.

    (a)

    Calculate the total number of atoms in two molecules of ammonia (NH₃). Show your working.

    [3 marks]
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  10. Question 10

    3 marks · Normal

    Explain why oxygen can exist as O₂ molecules, but helium does not form molecules under normal conditions. Use your knowledge of atoms and molecules.

    Answer and see the solution →