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GCSE Combined Science · key term
An atomic model with a tiny, positively charged central nucleus containing most of the atom’s mass, surrounded by electrons and mostly empty space.
Used by AQA and Edexcel
Specification 5.1.1.3, 6.4.1.3 · Paper 3, Paper 5
A model in which an atom has a tiny, positively charged central nucleus containing most of its mass, with electrons around it and mostly empty space between.
Revise: Development of the Atomic ModelRutherford’s nuclear model, proposed in 1911, placed most of the atom’s mass and its positive charge in a small central nucleus, with negative electrons around it.
Paper 5, Paper 6
An atomic model with a small, positively charged central nucleus containing nearly all the atom’s mass, surrounded by electrons, with most of the atom being empty space.
Revise: Development of the atomic modelRutherford’s nuclear model therefore placed a tiny, positively charged nucleus at the centre, containing nearly all the atom’s mass. Negatively charged electrons orbited at a distance, leaving most of the atom empty.
Bohr adapted the nuclear model; he did not discover the nucleus. Details of the experiments supporting Bohr’s model and Chadwick’s discovery are not required.
The plum pudding model already included electrons. Its key difference from the nuclear model was that positive charge was spread throughout the atom, rather than concentrated in a nucleus.
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