History of Atomic Theory

Flashcards reviewing the scientists and their contributions to the development of atomic theory.

Rydberg

Developed an equation to calculate the wavelengths emitted by a hydrogen atom.

Bohr

Proposed that electrons are in quantized energy levels. (Note: His atom model was ultimately incorrect.)

Planck

Proposed that energy itself is quantized.

Einstein

Explained the photoelectric effect.

De Broglie

Proposed that matter is quantized and exhibits both wave and particle-like properties.

George Thompson

Proved the wave-like properties of electrons.

John Dalton

Developed Atomic Theory: Matter is composed of atoms; atoms of the same element have the same properties; atoms combine in small, whole-number ratios; atoms are neither created, destroyed, nor changed in chemical reactions but simply rearranged.

J.J. Thompson

Discovered the electron and found the electron's charge/mass ratio.

Robert Millikan

Found the charge and mass of the electron.

Ernest Rutherford

Theorized that neutrons and protons reside in the nucleus of the atom, with electrons occupying the space outside the nucleus.

James Chadwick

Discovered the neutron which is neutral and has a similar mass to the proton.