The “original”

English scientist Theory proposed in 1803 Billiard Ball

◦ http://www.sciencemuseum.org.uk/images/I044/10312949.aspx

Matter is composed of small indivisible particles called atoms.

Atoms of an element are identical to each other and different from atoms of other elements.

Twins!!!!Different Twins!!!!

Atoms of different elements can combine in simple whole number ratios. It is possible to have more than one compound from the same 2 elements.

Chemical reactions occur when atoms are joined, separated, or rearranged. But, atoms of one element cannot be changed into atoms of a different element.

Atoms are divisible!!!!

Atoms of the same element are not identical. Isotopes, with different masses exist.