A student states that all atoms contain three types of subatomic particle. State the names of these three subatomic particles, give the relative charge of each one, and state where in the atom the majority of the mass is found.

WJEC GCSE Physics (Wales) — 2.4 The atom, the nucleus and radioactivity · State · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

Proton – +1
Neutron – 0
Electron – –1
The majority of the mass is found in the nucleus

Use the exact names (proton, neutron, electron) and their charges; include the nucleus detail
Write the charges in the correct order (+1, 0, –1)
Keep the answer concise – no extra words

Misspelling a particle name (e.g. ‘proton’ as ‘proton’ is fine, but ‘neutron’ as ‘neutron’ is wrong) Incorrect charge for the electron (writing +1 instead of –1) Forgetting to mention the nucleus as the location of most mass

Proton (named correctly)
Neutron and electron named (both required for the mark)
Correct relative charges: proton +1, neutron 0, electron −1 (all three correct for the mark)
The majority of the mass is found in the nucleus