scientists to know

Antoine Lavoisier

Law of Conservation of Mass, Father of Modern Chemistry

Democritus

first to suggest that matter consisted of small, invisible particles he called atomos

Aristotle

suggested that matter was infinitely divisible, thought all matter was composed of the four elements

John Dalton

published an Atomic Theory, Law of Multiple Proportions

Benjamin Franklin

first to designate charges as positive and negative, experiments with electricity

Humphry Davy

used electrolysis to propose that the elements in compounds were held together by electrical forces

Michael Faraday

determined the quantitative relationship between the electricity used in electrolysis and the extent to which the chemical reaction occurred, developed laws of electrolysis

George Stoney

suggested that the electric charge was associated with the atoms, suggested that the units of electric charge be called electrons

Henri Becquerel

discovered radioactivity when uranium darkened a photographic plate in the absence of light, identified radioactive substances

Ernest Rutherford

discovered the atomic nucleus and where the positive charges were located in an atom using the gold foil experiment, characterized the three types of radiation

J.J. Thomson

performed cathode ray tube experiments to discover that electrons are fundamental particles present in all matter, Plum Pudding Model (negative electrons were embedded in a sea of positive charge)

Robert Millikan

designed the oil drop experiment to determine the fundamental charge of the electron

Eugene Goldstein

observed that a CRT also has a stream of positive rays that go from the anode to the cathode which were later identified as protons

H.G.J. Moseley

studied X-rays given off by different elements, developed the concept of the atomic number, Moseley’s Law states that an element’s identity is determined by the number of protons not the atomic weight

James Chadwick

discovered the nuetron and that its uncharged and located in the nucleus