Honors Chem - Atomic Theory

History of atomic theory

Indestructible atoms

Dalton

Law of the Conservation of Matter (early)

Dalton

The same elements have identical atoms and vice versa

Dalton

Compounds are 2 elements’ atoms combined

Dalton

Discoveries made with subatomic particles & isotope(?)

Dalton

Discoveries discarded because: NOT same element, same atoms; NOT indestructible atoms

Dalton

Simple circle atom model

Dalton

Negatively charged electrons

Thomson

Plum pudding model

Thomson

Cathode ray experiments

Thomson

Discoveries discarded because: more subatomic particles than assumed; no goo

Thomson

Amount of charge in electron

Milikan

Oil drop experiments

Milikan

Discovered nucleus 

Rutherford

Discovered protons

Rutherford

Found that atoms are mostly empty space

Rutherford

Gold foil experiment

Rutherford

Discoveries discarded because: atoms would collapse if assumed true; another subatomic particle

Rutherford

Nuclear model (dot, ovals)

Rutherford

Planetary model (center, rings)

Bohr

Claimed electrons were in orbits/energy levels & could jump between them

Bohr

Used math

Bohr

Discoveries discarded because: atoms don’t stay neatly in line

Bohr

discovered neutrons & that they were slightly bigger than protons

Chadwick

smashed Beryllium to make discoveries

Chadwick

electron cloud model

Schrodinger & Heisenberg

Cannot predict where electrons will be, but can find probabilities

Schrodinger & Heisenberg