Atomic Structure

Developing Ideas:

Boyle - Proposes some substances cannot be made smaller

Dalton - Suggests elements are made up of atoms, and different atoms have different masses

Becquerel - Discovers radioactivity, showing particles can come from inside an atom

JJ Thompson - Discovers electrons and negative charge, also suggests plum pudding model

Rutherford - Found that atoms are made up of sub-atomic particles.

Sub-Atomic Particles:

Protons - Positive charge, Mass 1, found in nucleus

Neutrons - No charge, Mass 1, found in nucleus

Electrons - Negative charge, orbits the nucleus in shells, negligible mass

1913 - Bohr suggests that atoms are like small solar systems with electrons orbiting a positive nucleus.

1932 - Chadwick discovers the neutron.

Electron Shells: