Chem Ch.4 scientists

alchemists

performed reactions without careful measurements or recording information

Robert Boyle

the first to perform accurate measurements and recordings of chemical reactions, wrote "The Skeptic Chemists"

George Stahl

suggested that fire produced a substance called phlogiston

Joseph Priestly

disproved the phlogiston theory and is given credit for discovering oxygen, but not naming it

Antoine Lavoisier

explained the true nature of combustion and gave oxygen it's name

Joseph Proust

Law of Definite Proportion

John Dalton

Wrote "New Systems of Chemical Philosophy", Law of Multiple Proportions, Dalton's Law of partial pressures

Humphry Davy

discovered several alkali and alkaline earth metals and the elemental nature of chlorine and iodine

Jons Jakob Berzelius

discovered cerium, selenium, silicon, and thorium, made modern system of using symbols for elements

Dmitri Mendeleev

gave us modern day sequence of the periodic table

Eugen Goldstein

discovered protons, he called them canal rays

J.J. Thomson

used the cathode ray tube to discover the electron and calculate the charge to mass ratio equation for the electron

Robert Millikan

oil droplet experiment; was able to determine the magnitude of the electron charge, using Thomson's equation was able to determine the mass of an electron

Ernest Rutherford

gold foil experiment; atoms consisted of a sparsely occupied electron field and a dense positively charged center (nucleus)

Francis Aston

invented mass spectrometer, proved existence of isotopes