atom timeline

Aristotle

401 BCE

said atoms didn't exist

Democritus

400 BCE

adopted the atomic theory: Said all matter was formed of different types of tiny discrete particles and that the properties of these particles also determine the properties of the matter

Antonie Lavosier

Oct 4, 1786

created the law of conservation of matter

Joseph Proust

Oct 4, 1793

created the proust law

John Dalton

Oct 4, 1800

said all matter was made of atoms, all atoms are indivisible and indestructible. All atoms of a given element are identical in mass and properties. also that compounds were made of 2 different atoms and that a chemical reaction is the atoms rearranged

Amadeo Avagadro

Oct 4, 1811

first scientist to realize that elements could exist as molecules rather than as individual atoms

William Crookes

Oct 4, 1873

discovered the atomic weight

Henri Becquerel

Oct 4, 1896

discovered radioactivity

Ernest Rutherford

Oct 4, 1900

made the nuclear structure of an atom

Max Planck

Oct 4, 1900

found a way to describe the behavior of particles of the atomic scale

Madame Curie

Oct 4, 1903

pioneer radioactivity

J.J. Thomson

Oct 4, 1904

suggested the model of the atom in a sphere of positive matter which electrons are positioned by electrostatic forces

Robert Millikan

Oct 4, 1908

measured the charge of an electron

Henry Moseley

Oct 4, 1913

published the results of his measurements of the wavelengths of the X-ray spectral lines of a number of elements which showed that the ordering of the wavelengths of the X-ray emissions of the elements coincided with the ordering of the elements by atomic number.

start of WW1

Oct 4, 1914

start of ww1

Albert Einstein

Oct 4, 1921

made the famous equation E=mc^2

Niels Bohr

Oct 4, 1922

explained what was happening in side the atom structure and was the first to discover electrons travel in separate orbits

Erwin Schrodinger

Oct 4, 1926

took Bohr's atom model one step futher and used mathematical equations to find the certain stop of the electron

Louis deBroglie

Oct 4, 1929

predicting the wave nature or electrons

James Chadwick

Oct 4, 1932

proved the existence of neutrons

Start of ww2

Oct 4, 1939

start of WW2

Manhattan project

Oct 4, 1942

test first neuclear weapon

hiroshima

Oct 4, 1945

first atomic bomb

trinity test

Oct 4, 1945

tested a bomb

Werner Heisenberg

Oct 4, 1958

calculated the behavior of electrons and subatomic particles that also make an atom