Inside the Atom Theories
by Neave Hancock-Wolfe
1. Rutherford (1911)
1.1. Proposed that the atom consisted mostly of space with a dense nucleus containing protons.
1.1.1. The only flaw in this model was that it proposed that the orbiting electrons would eventually lose energy and spiral towards the nucleus.
1.2. Negatively charged electrons orbit the nucleus.
2. Bohr (1913)
2.1. Modified Rutherford’s model by suggesting that electrons orbit the nucleus at different energy levels.
3. Chadwick (1932)
3.1. Discovered that the nucleus contained particles called neutrons, as well as protons
4. Democritus (400 bc)
4.1. Suggested that all substances consisted of tiny indestructible particles called atoms.
5. Dalton (1808)
5.1. Atomic theory proposed
5.1.1. All matter consisted of tiny particles called atoms.
5.1.2. Atoms could not be divided into smaller particles.
5.1.3. Atoms of the same element were alike.
5.1.4. Atoms combined in simple whole ratios.
6. Thomson (1897)
6.1. Explained that the atom contained negatively charged particles called electrons
6.1.1. His model suggested atoms were positively charged spheres with embedded electrons.
6.1.2. Otherwise known as ’the plum pudding model’