Honors Chemistry-Important People Semester 1

Democritus

Greek philosopher: suggested everything is make up of time particles called “atomos”

Aristotle

Greek philosopher: tought that everything was makeup of the “fundamental elements”: earth, wind, fire, water

John Dalton

English meteorologist and chemist: proposed that atoms are tiny, solid, indivisible particles and Dalton’s Atomic Theory and billiard ball model of atom

John Dalton

Law of Multiple Proportions: elements combine to make compounds by making whole number ratios

J.J. Thomson

Cathode Ray experiment that deduced the existence of tiny negatively charged particles he named electrons. Makes Plum Pudding Model of atom

Ernest Rutherford

discovers atomic nucleus during Gold-foil experiment; makes nuclear model of atom

Neils Bohr

develops Solar System model of atom that electrons circle nucleus in energy levels

James Chadwick

British physicist: discovered neutron

Quantum Mechanical Model

uses shapes of orbitals to model volumes of space where there is likely an electron-probability of finding electron in the space