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Science
Atoms, elements and compounds

Starter quiz

  • Which element does the chemical symbol 'O' represent?
    • 'oxygen' ✓
  • In the chemical formula CO₂, what element does 'C' represent?
    • 'carbon' ✓
  • Which of the following is a molecule?
    • Na
    • H₂O  ✓
    • Mg
    • NH₃  ✓
  • Match the chemical formula to the correct substance.
    • oxygen atom
      ⇔
      O ✓
    • elemental oxygen
      ⇔
      O₂ ✓
    • molecule made of hydrogen and oxygen
      ⇔
      H₂O ✓
    • molecule of hydrogen
      ⇔
      H₂ ✓
  • Each ______ is represented by its own chemical symbol, for example 'K', 'Fe' or 'C'.
    • 'element' ✓
  • Match each term with its correct definition.
    • element
      ⇔
      A substance that cannot be broken down into simpler substances. ✓
    • atom
      ⇔
      The smallest unit of a chemical element. ✓
    • matter
      ⇔
      Anything that has mass and takes up space. ✓
    • pure
      ⇔
      A substance composed of only one chemical substance. ✓
    • molecule
      ⇔
      Two or more atoms bonded together (usually non-metals). ✓
    • compound
      ⇔
      Two or more different types of atoms bonded together. ✓
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