Scientists
John Dalton (1766-1844); Discovery 1803:
Atomic Theory
Conservation of Mass
Law of Multiple Proportions
Dalton’s Atomic Theory
1. All matter consists of indivisible particles called atoms.
2. Atoms of the same element are similar in shape and mass,
but differ from the atoms of other elements.
3. Atoms cannot be created or destroyed.
4. Atoms of different elements may combine with each other
in a fixed, simple, whole number ratios to form compound
atoms.
5. Atoms of same element can combine in more than one
ratio to form two or more compounds.
6. The atom is the smallest unit of matter that can take part
in a chemical reaction.
