Structure of atoms

1. JJ Thomson

1.1. Discovered electrons (he discovered the atoms repelled negative charges) theorized there was a positive charge somewhere

2. William Thomson/Lord Kelvin

2.1. Plum pudding: pudding= positive and raisins= electrons

3. Rutherford

3.1. - discovers positive particles in atoms (protons) - discovers an atomic nucleus (nuclear atom) -disproves Lord Kelvin's plum pudding model (foil exp. positive beam deflected)

3.1.1. him and James Chadwick discover neutrons in the nucleus (these are bigger than protons and electrons)

4. Democritus

4.1. "Atomos": indivisible, tiny particles, first prophet of the atomic theory (no data)

5. Dalton

5.1. atoms were indivisible, tiny particles (has data) Atoms can form compounds in definite proportions