Page 190 - Science Course 1 (Book 1)

Mo6-L1a: How did the Atomic Theory Start?

Dalton’s Atomic Model The Atom

John Dalton combined Atoms of different elements are different sizes,
data from his own but all are very, very small.
scientific research with
data from the research You cannot see atoms with just your eyes or even
of other scientists to with most microscopes.
propose a new atomic hydrogen atom hydrogen atom carbon atom
theory. (1 proton) (1 proton) (6 protons)

John Dalton’s Atomic Theory

All matter is made of of atoms that Key Concept
1 cannot be divided, created, or destroyed. How did the Atomic Theory Start?

During a chemical reaction, atoms of How would you describe the size of an Atom?
2 one element cannot be converted into
atoms of another element.

3 Atoms of one element are identical to
each other but different from atoms of
another element.

4 Atoms combine in specific ratios.

Greeks: atoms determined properties

WATER

IRON
Dalton: atoms determined properties

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