Atomic Theory People

______

Derived an equation that showed how electrons travel around the nucleus as a wave

1. Albert Einstein

______

Determined that the mass of the electron was much less than that of a hydrogen atom

1. Aristotle

______

Discovered negatively-charged particles in the green flash of a cathode ray tube

1. Democritus

______

Discovered that atoms of each element have different numbers of protons

1. Ernest Rutherford

______

Discovered the neutron

1. Erwin Schrödinger

______

Discovered the nucleus using the gold foil experiment

1. Henry Moseley

______

Expanded on the work of Democritus; came up with six-part atomic theory

1. J.J. Thomson

______

First thought matter was made up of tiny particles called atoms

1. James Chadwick

______

Found the charge and mass of an electron using the oil-drop experiment

1. John Dalton

______

Proposed that electrons have wave-like behavior

1. Louis de Broglie

______

Proposed that electrons orbit the nucleus in specific paths, like planets orbit the sun

1. Max Planck

______

Proposed that light has a dual nature; stated that light can be thought of as a beam of photons

1. Niels Bohr

______

Proposed that matter can gain or lose energy only in small, specific amounts (called quanta)

1. Robert Millikan

______

Proposed the plum pudding model of the atom

1. Sir William Crookes

______

Thought matter was made up of four elements: earth, fire, water, and air

______

Discovered the proton