Question
Question (3 marks): Carbon, oxygen and iron atoms in your body did not exist when the universe began. Explain where they came from.
Mark scheme (3 marks):
- The early universe contained only hydrogen and helium (and trace lithium) — 1 mark.
- Elements up to iron were produced by nuclear fusion in the cores of stars (especially massive stars) — 1 mark.
- Elements heavier than iron / dispersal of all these elements into space occurred during supernova explosions, later forming new stars and planets — 1 mark.
3 marks · take your time before peeking.
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Generated by TopMyGrade AI · cross-check official sources before relying on the mark-scheme phrasing.