Atomic Models

Chem 101 Atomic Models and Experiments

Dalton

Atmoic Theory - atoms are the building blocks of everything

• Atoms are indivisible

• Atoms cannot change their identity

• Atoms have a unique mass

• Atoms combine to form compounds

JJ Thomson

Plum Pudding Model

• Discovery of the electron

• Atoms must have positive and negative charges

Harvey Fletcher

Milikan oil drop theory

• Proved electrons are particles

• Could extract charges from oil droplets

Marie Curie

• Discovered radioactivity

• Atoms myst be made of smaller particles

Rutherford

Rutherford model

• Discovered the proton

• Small nucleus with high charge and lots of mass

Bohr

Planetary system model

• base of electron configuration

• electrons orbit the nucleus

Quantum mechanics model

• current model used today

• atoms are extremely small with smaller nucleus