Monica:)

Democritus

400

Democritus said that matter is made up of atoms.

John Dalton

Jan 1, 1803

Dalton proposed an atomic theory: that elements consisted of tiny particles called atoms. Also it is made up of spherical masses and motions.

JJ Thomson

Jan 1, 1897

Thomson discoverd the electron.
He descibed the atom as a ball of positive charge containing a number of electrons.
Thomson's model is known as chocalate chip model in U.S.

Ernest Rutherford

Jan 1, 1911

He used his "gold foil" experiment to determine that the nucleus of the atom is very dense and had a positive charge.
Rutherford discovered the proton.
Also, he assumed that the electrons were oustide the nucleus of the atom.

Neils Bohr

Jan 1, 1922

Bohr explained the atomic structure of the atom is "successive" orbital shells of electrons
This is known as Bohr Plantary model.

Schrodinger

Jan 1, 1926

Schrodinger and de Broglie identified the electron cloud model as the probable location of moving electrons.

James Chadwick

Jan 1, 1932

Chadwick discovered a particle within the nucleus that has a mass similar to that of a proton.
He is credited for discovering the neutron.

Harry S. Truman

Aug 6, 1945

Made the decision to drob the atomic bomb on Hiroshima and Nagasaki.

Building of Atomic Bomb

Sep 28, 1945

Voltage multiplier is associated with the building of the atomic bomb.
Cockroft and Walton influenced this idea.

Nuclear Power Accident

Apr 25, 1986

-A nuclear reactor blew up in Chernobyl.
-30 people died and 130,000 had to be evacuated do to the radiation levels.