jul 31, 1814 - John Dalton's Model of the Atom
Dalton proposed that the atom is a solid, indivisible, indestructible sphere and that the atom contains no subatomic particles. Subatomic particles are particles smaller than an atom. Dalton's theory was that: 1. All elements are made of atoms which are indivisible and indestructible particles. 2. Atoms of the same element are exactly the same, having the same mass and chemically behaving the same. 3. Every element is characterized by the mass of it's atoms. Different elements have atoms that are different in mass and chemical properties from the atoms of each other element. 4. When two or more atoms from different elements connect they create compounds. 5. Atoms aren't created or destroyed in a chemical change. This theory is now referred to as the "billiard ball" model. His theory helped to advance the atomic theory, however, some of his theory was incorrect.
Added to timeline:
The Atomic Theory