Dalton's Atomic Theory

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Dalton was an English school teacher who became a scientist, good move on his part! Anyway, in 1808 Dalton

summarized a new atomic theory concerning the nature of atoms. Dalton's theory was the first theory concerning atoms since Democratis and Aristotle of ancient Greece. Daltons base his new theory on atoms in five parts:

1. All matter is made up of small invisible particles called atoms.

2. Atoms cannot be created, destroyed or subdivided.

3. Atoms of the same element are identical in their physical properties and atoms of different elements have different physical properties that distinguished them from different atoms of different elements.

4. Atoms in chemical reactions can combine, rearrange and separate.

5. Atoms of different elements form compounds in simple whole number ratios.

Dalton's Atomic Theory is still used today with the exception of rule three in nuclear reactions we create, subdivide or destroy atoms.