AQA GCSE · Question 09.2 · Atomic structure and the periodic table
Atoms contain electrons, neutrons and protons. Write these three particles in order of their discovery.\n\nEarliest \n\nLatest ______
How to approach this question
Recall the history of the discovery of subatomic particles. The first particle to be discovered was the electron, which led to the plum pudding model. The proton and the nucleus were discovered next, leading to the nuclear model. The neutron was the last of the three to be discovered because it has no charge, making it difficult to detect.
Full Answer
Earliest: Electron\nProton\nLatest: Neutron
The historical order of discovery of the main subatomic particles is:\n1. **Electron (1897):** Discovered by J.J. Thomson, leading to the plum pudding model.\n2. **Proton (1917-1919):** Discovered by Ernest Rutherford, who also discovered the nucleus in his gold foil experiment (1909), leading to the nuclear model.\n3. **Neutron (1932):** Discovered by James Chadwick. Its discovery was much later because its lack of electrical charge made it very difficult to detect.
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