Atomic Theory Timeline

Scientists That Contributed to Modern Atomic Theory

John Dalton

1803

In 1803 Dalton unveiled his concept of Dalton's Law of Particle Pressures. Also first scientist to connect the behavior of atoms to their weight.

Eugen Goldstein

1886

Eugen Goldstein discovered cathode rays and anode rays.

J.J. Thomson

1897

J.J. Thomson discovered the electron and also discovered that elements have different isotopes. Won the Nobel Prize in 1906.

Max Planck

1900

In 1900 Max Planck published a paper showing the relationship between the energy and the frequency of radiation, which is now called Planck's constant.

Ernest Rutherford

1904

Ernest Rutherford introduced the idea of an element radioactively decaying into a different element. Also introduced a model of an atom. Also discovered the proton. He was awarded the Nobel Prize in 1908 for Chemistry.

Albert Einstein

1905

In 1905 Albert Einstein published his paper on the Theory of Relativity. For his explanation of the photoelectric effect, Einstein won the Nobel Prize for Physics in 1921.

Robert Millikan

1910

Robert Millikan successfully determined the charge of electrons. For his work Millikan was awarded the Nobel Prize in 1923.

Henry Moseley

1913

Henry Moseley used X-Rays to study the atomic structure. His discoveries led to a better organized periodic table.

Neils Bohr

1922

Neils Bohr concludes that an atom has different energy levels, and that when an atom receives a quanta of energy it jumps a level, and when it radiates a quanta is falls a level.

Louis deBroglie

1923

Louis deBroglie is famous for his work on the wave mechanics of electrons. He was awarded the Nobel Prize in 1929 in Physics.

Werner Heisenberg

1925

In 1925, Heisenberg published his theory of quantum mechanics. He is also famous for his principle of uncertainty. For his work on quantum mechanics, Heisenberg was awarded the Nobel Prize for Physics in 1932.

Erwin Schrodinger

1926

In 1926, Erwin Schrodinger published papers that would provide the foundations for quantum wave mechanics. In 1933 he shared the Nobel Prize with another physicist.

James Chadwick

1932

In 1932 James Chadwick discovered the neutron. He published his findings in his paper, "Possible Existence of Neutron." Won Nobel Prize in 1935.

Biology, Chemistry, and Physics

Joseph Priestley

1774

Discovered oxygen, carbon monoxide, and nitrogen dioxide

Antoine Lavoisier

1789

Law of Conservation of mass; father of modern chemistry

Alessandro Volta

1799

Electrochemical cell and batteries

Michael Faraday

1831

Electricity and electrochemistry

Louis Pasteur

1862

pasteurization process

Alfred Nobel

1867

Dynamite, Nobel Prize

Henri Becquerel

1896

radioactivity

Guglielmo Marconi

1896

Radio

Marie Curie

1914

Radioactivity

Sir Frederick Banting

1921

isolated insulin

Philo Farnsworth

1927

TV

Wallace Carothers

1928

Neoprene and nylon

Leo Szilard

1942

Nuclear Chain Reactions and atomic bomb

Kary Mullis

1983

Polymerase Chain Reaction

Historical Events

Gutenberg Printing Press

1436

Discovery of Americas

1492

Reformation of the Catholic Church

1517

Galileo Convicted of Heresy

April 12, 1633

Declaration of Independence

July 4, 1776

Civil War

April 12, 1861 - May 9, 1865

First Transcontinental Railroad in US

1863 - 1869

Assassination of Archduke Ferdinand

June 28, 1914

Bolshevik Revolution

1917

Treaty of Versailles

June 28, 1919

Bombing of Pearl Harbor

December 7, 1941

First Cellular Phone

April 3, 1973

Initial Concept for World Wide Web

March 1989