Science Chapter Review- Matter and Elements

Review Chapter 3

Timeline of our understanding of elements pg 82-85

Democritus proposed that the smallest indivisible amount of matter that still retained the properties of that substance was an atom.

Alchemists: mixture of science and witchcraft. Tried to change lead into gold. Failed

Dalton: First to recognize Oxygen as an element. Believed every element had its own kind of atoms.

Thomson: Believed that the atom was made up of charged particles. Negative electrons were interspersed throughout the positive Nucleus. Kind of like a "Plum Pudding".

Rutherford: Believed that the Atom was mostly empty space. With a small compact Nucleus and electrons orbiting like planets.

Bohr: Created a model of the atom with a nucleus with Protons and Neutrons and a series of Electron orbiting around the nucleus.