Timeline Project

Events

Democritus

400 BC

Atomic Hypothesis = everything is made of atoms

Aristotle

322 BC

Helped develop zoology further

Lavoisier

1743 - 1794

Matter cannot be destroyed or created

Dalton

1803

He said that everything is made of atoms

Avogadro

1811

he made Avogadro’s Law. Equal volumes =equal molecules

Berzelius

1823

discovered the element silicon. He also discovered selenium, thorium, and cerium

Curie M.

1866 - 1934

She discovered X-rays

Bohr

1885 - 1962

He developed an early model of the atoms where electrons circle around the nucleus.

Moseley

1887

Developed the application of X-Ray Spectra to study atomic structure

Mendeleev

1896

he published the periodic table

Becquerel

1896

He discovered radioactivity

Thompson

1897

Thompson created the cathode ray

Millikan

1909

Oil drop experiment determined the size of the charge of an electron

Rutherford

1917

with the gold foil experiment he discovered the nucleus

Planck

1918

He came up with the idea of quantum theory

Heisenberg

1925

Theory of quantum mechanics

Schrodinger

1926

Schrodinger’s Cat was an experiment that created a paradox. If a cat was put in a box with a vial of poison rigged to go off at a random time they wouldn’t know whether it was dead or alive. The cat could be alive and dead simultaneously, but they wouldn’t know until they opened the box.

Chadwick

1932

He discovered the neutron

Meitner

1945

He discovered nuclear fission