Chemistry timeline. Web 2.0

By rogelio22
  • 440

    Democritus

    Democritus speculates about fundamental indivisible particles—calls them "atoms"

  • Henry Cavendish

    Henry Cavendish ' >://en.wikipedia.org/wiki/Henry_Cavendish' >Henry Cavendish</a> </a>discovers and studies hydrogen

  • Carl Scheele and Antoine Lavoisier

    1778 [Carl Scheele and Antoine Lavoisier](http://en.wikipedia.org/wiki/Carl_Scheele, http://en.wikipedia.org/wiki/Antoine_Lavoisier) discover that air is composed mostly of nitrogen and oxygen

  • Joseph Priestley

    Joseph Priestley creates water by igniting hydrogen and oxygen

  • William Nicholson and Anthony Carlisle

    William Nicholson and Anthony Carlisle use electrolysis to separate water into hydrogen and oxygen

  • John Dalton

    John Dalton introduces atomic ideas into chemistry and states that matter is composed of atoms of different weights

  • Thomas Young

    Thomas Young conducts Double-slit experiment (approximate time)

  • Amedeo Avogadro

    Amedeo Avogadro claims that equal volumes of gases should contain equal numbers of molecules

  • Michael Faraday

    1832 Michael Faraday states his laws of electrolysis

  • Dmitri Ivanovich Mendeleev

    Dmitri Ivanovich Mendeleev systematically examines the periodic table and predicts the existence of gallium, scandium, and germanium

  • Johannes van der Waals

    Johannes van der Waals introduces the idea of weak attractive forces between molecules

  • Johann Balmer

    Johann Balmer finds a mathematical expression for observed hydrogen line wavelengths

  • Heinrich Hertz

    Heinrich Hertz discovers the photoelectric effect

  • Lord Rayleigh and William Ramsay

    Lord Rayleigh and William Ramsay discover argon by spectroscopically analyzing the gas left over after nitrogen and oxygen are removed from air

  • William Ramsay

    William Ramsay discovers terrestrial helium by spectroscopically analyzing gas produced by decaying uranium

  • Antoine Becquerel

    Antoine Becquerel discovers the radioactivity of uranium

  • Pieter Zeeman

    1896 [Pieter Zeeman](http://en.wikipedia.org/wiki/Pieter_Zeeman) studies the splitting of sodium D lines when sodium is held in a flame between strong magnetic poles

  • J.J. Thomson

    J.J. Thomson discovers the electron

  • William Ramsay and Morris Travers

    William Ramsay and Morris Travers discover neon, and negatively charged beta particles

  • Paul Villard

    Paul Villard discovers gamma-rays while studying uranium decay

  • Johannes Rydberg

    Johannes Rydberg refines the expression for observed hydrogen line wavelengths

  • Max Planck

    Max Planck states his quantum hypothesis and blackbody radiation law

  • Philipp Lenard

    Philipp Lenard observes that maximum photoelectron energies are independent of illuminating intensity but depend on frequency

  • Theodor Svedberg

    Theodor Svedberg suggests that fluctuations in molecular bombardment cause the Brownian motion

  • Albert Einstein

    Albert Einstein explains the photoelectric effect

  • Charles Barkla

    Charles Barkla discovers that each element has a characteristic X-ray and that the degree of penetration of these X-rays is related to the atomic weight of the element

  • Hans Geiger and Ernest Marsden

    Hans Geiger and Ernest Marsden discover large angle deflections of alpha particles by thin metal foils

  • Ernest Rutherford and Thomas Royds

    Ernest Rutherford and Thomas Royds demonstrate that alpha particles are doubly ionized helium atoms

  • Ernest Rutherford

    Ernest Rutherford explains the Geiger-Marsden experiment by invoking a nuclear atom model and derives the Rutherford cross section

  • Jean Perrin

    Jean Perrin proves the existence of atoms and molecules

  • Max von Laue

    Max von Laue suggests using crystal lattices to diffract X-rays

  • Walter Friedrich and Paul Knipping

    Walter Friedrich and Paul Knipping diffract X-rays in zinc blende

  • William Henry Bragg and William Lawrence Bragg

    William Henry Bragg and William Lawrence Bragg work out the Bragg condition for strong X-ray reflection

  • Henry Moseley

    Henry Moseley shows that nuclear charge is the real basis for numbering the elements

  • Niels Bohr

    NNiels Bohr presents his quantum model of the atom

  • Robert Millikan

    Robert Millikan measures the fundamental unit of electric charge

  • Johannes Stark

    Johannes Stark demonstrates that strong electric fields will split the Balmer spectral line series of hydrogen

  • James Franck and Gustav Hertz

    James Franck and Gustav Hertz observe atomic excitation

  • Ernest Rutherford

    Ernest Rutherford suggests that the positively charged atomic nucleus contains protons

  • Arnold Sommerfeld

    Arnold Sommerfeld develops a modified Bohr atomic model with elliptic orbits to explain relativistic fine structure

  • Gilbert N. Lewis and Irving Langmuir

    Gilbert N. Lewis and Irving Langmuir formulate an electron shell model of chemical bonding

  • Albert Einstein

    Albert Einstein introduces the idea of stimulated radiation emission

  • Alfred Landé

    Alfred Landé introduces the Landé g-factor

  • Arthur Compton

    Arthur Compton studies X-ray photon scattering by electrons

  • Otto Stern and Walther Gerlach

    Otto Stern and Walther Gerlach show "space quantization"

  • Louis de Broglie

    Louis de Broglie suggests that electrons may have wavelike properties

  • Lise Meitner

    Lise Meitner discovers the Auger process

  • John Lennard-Jones

    John Lennard-Jones proposes a semiempirical interatomic force law

  • Satyendra Bose and Albert Einstein

    Satyendra Bose and Albert Einstein introduce Bose-Einstein statistics

  • Wolfgang Pauli

    Wolfgang Pauli states the quantum exclusion principle

  • Linus Pauling

    discovers resonance bonding and uses it to explain the high stability of symmetric planar molecules

  • John Cockcroft and Ernest Walton

    John Cockcroft and Ernest Walton split lithium and boron nuclei using proton bombardment

  • 1933 Max Delbruck

    1933 Max Delbruck suggests that quantum effects will cause photons to be scattered by an external electric field

  • Irène Joliot-Curie and Frédéric Joliot

    1934 Irène Joliot-Curie and Frédéric Joliot bombard aluminum atoms with alpha particles to create artificially radioactive phosphorus-30

  • Enrico Fermi

    1942 Enrico Fermi makes the first controlled nuclear chain reaction

  • Large Hadron Collider

    2008 The Large Hadron Collider at CERN is scheduled to begin operation in this year. Its primary goal is to search for the Higgs boson, which has not yet been found.