Who did what in chemistry?

Ancient Greeks Democritus suggested that all matter was made up of atoms.

John Dalton Atomic Theory Matter is made from very small particles called atoms Atoms are indivisible Atoms cannot be created or destroyed

William Crookes Radiation from Cathode rays

J.J Thomson Discovery of electron Plumb pudding model of atom structure

George Stoney Irish UCG Suggested the name ‘electron’

Robert Millikan Size and charge of electron Oil drop experiment

Ernest Rutherford Discovery of nucleus Discovery of proton

James Chadwick Discovery of the neutron

Neils Bohr Study of emission line spectra Electrons in fixed orbits n=1 n=2 etc Have fixed amount of energy, energy levels Can gain or lose energy by moving between energy levels

Louis De Broglie Electrons move with a wave motion

Heisenberg Uncertainty principle Impossible to measure velocity and position of electron at the same time Probability of finding an electron at a particular position

Schrodingner Developed wave equations to identify orbital shapes ‘S’ orbitals are spherical ‘P’ orbitals are dumb-bell shaped

Robert Boyle Irish, Co. Waterford First definition of an element Predicted that elements combine in a chemical reaction Boyle’s Law: at const temp the volume of a fixed mass of gas is inversely proportional to its pressure

Humphrey Davy Exploited Electrochemistry Discovered elements Na and K

Dobereiner Grouped elements into Triads Grouped according to Atomic Mass

Newlands Grouped elements into Octaves 1st and 8th element had similar properties Noble gases had not been discovered, he did not leave gaps

Dmitri Mendeleev Periodic law Elements arranged increasing RAM Left gaps Some in reverse order

Moseley Determined the atomic number of elements Arranged elements in order of Atomic Number

Friederichn Hund Maximum Multiplicity: when two or more orbitals of equal energy are available, the electrons occupy them singly first

Wolfgang Pauli No more than two electrons can occupy an orbital Electrons in an orbital must have opposite spin

Alessandro Volta Invented the battery

Luigi Galvani Discovered animal electricity

Joseph Gay-Lussac The law of combining volumes of gases Developed volumetric analysis

Carlo Avogadro Method for finding molecular formulae

Michael Faraday Discovered laws of electrolysis Discovered Benzene Invented: electric motor, dynamo and transformer

Henri Le Chatelier Le Chatelier principle

William Henry Bragg William Lawrence Bragg Father and son Developed the X-ray diffraction method for determining crystal structures

J.N.Bronsted T.M.Lowry Proposed the modern definitions of acids and bases