history of atoms

1.

Democritus

2.

John Dalton

3

JJ Thomson

4.

Ernest Rutherford

5.

Chadwick

Democritus discovery:

• unbreakable particles

• different particles for each different substance

• called it “atomis”

Democritus tool

none he just though abt dividing matter until it couldnt be divided anymore

democritus atomic model

John Dalton dsicovered

• all atoms of the same element are identical

• different elements have different types of atoms

John Dalton tool

no specific tech

John Dalton atomic model

JJ thomson

discovered: PLUM PUDDING MODEL

• electrons were present in every kind of atom tested → all atoms contain small negative particles

JJ Thomson tool:

Cathode Ray Tubes

JJ Thomson atomic model:

Ernest Rutherford discovery

suggested that atoms were mostly empty space with a tiny dense and positively charged nucleus in the middle

Ernest Rutherford tool

metal foils

Ernest Rutherford atomic model:

James Chadwick discovery:

neutrons

James Chadwick tool: Geiger counter