John dalton
All matter is made of tiny indivisible particles called atoms.
Atoms of the same element are identical.
Atoms combine in simple whole-number ratios to form compounds.
John dalton’s model
Billiard ball model
John dalton limitations
Didn’t know about subatomic particles.
Michael farady model
Model: Not a visual model — just the idea that atoms involve electrical forces.
Michael Faraday
Discovered electrical nature of atoms.
Proposed that atoms could gain or lose charges, forming ions.
Connected electricity to chemical bonding.
Thomson
Discovered the electron using cathode ray tubes.
Determined electrons are negatively charged and much smaller than atoms.
Thomson model
Plum pudding mode- positive dough with electrons embedded inside
Why was Thomson’s model special
First atomic structure model to include subatomic particles.
Rutherford
Gold foil experiment → discovered:
Positive charge and most mass is in a tiny nucleus
Atoms are mostly empty space
Electrons orbit around the nucleus
Rutherford model
Model: Nuclear model (tiny nucleus, electrons around it)
What did Rutherford do for Bohr
Set stage
Bohr diagram
a visual representation of an atom that shows a central nucleus (containing protons and neutrons) surrounded by electrons orbiting in specific
