Atomic Model Timeline

Cheyenne Cink

John Dalton Model of the Atom (1803)

Dalton pictures atoms as tiny, indestructible particles, with no internal structure.

J.J Thomson Model of the Atom (1897)

Discovers the electron, leading to his "plum pudding, chocolate chip cookie dough" model. He pictures electrons embedded in a sphere of positive electric charge.

Hantaro Nagaoko Model of the Atom (1904)

Nagaoka suggested that an atom has a central nucleus. Electrons move in orbits like the rings around Saturn.

Ernest Rutherford Model of the Atom (1911)

That an atom has a dense, positively charged nucleus. Electrons move randomly in the space around the nucleus.

Niels Bohr Model of the Atom (1913)

In Bohr's model, the electrons move in spherical orbits at fixed distances from the nucleus.

Louis de Broglie Model of the Atom (1924)

Proposed that moving particles like electrons have some properties of waves. Within the next few years, evidence was collected to support the idea.

Erwin Shrodinger Electron Cloud Model of the Atom (1926)

Develops mathematical equations to describe the motion of electrons in atoms. Shrodinger's work leads to the electron cloud model.

James Chadwick Model of the Atom (1932)

Confirms the existence of neutrons. Atomic nuclei contain neutrons and positively charged protons.