Atoms and molecules
2 marks · EasyExplain the difference between an atom of oxygen (O) and a molecule of oxygen (O₂).
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An atom of oxygen (O) is a single oxygen particle, while a molecule of oxygen (O₂) consists of two oxygen atoms chemically bonded together.
Also accept: O is one atom of oxygen; O₂ is two oxygen atoms bonded.; O is a single particle; O₂ is a molecule made of two oxygen atoms
Common mistakes: Calling O an atom and O₂ an element (O₂ is also an element, but a molecule)
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Marking points
B1 · 1 mark · States O is a single atom; O₂ is two atoms of oxygen bonded together.
B1 · 1 mark · Explains that O₂ is formed when two atoms are chemically bonded.
Worked solution
An atom of oxygen (O) is a single oxygen atom. A molecule of oxygen (O₂) is made when two oxygen atoms are joined together by a chemical bond.