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Lavoisier
A French chemist who proved the conservation of matter
and explained the mysteries of fire. -
Joseph Louis Proust
Proust%u2019s largest accomplishment into the realm of science was disproving Berthollet with the law of definite proportions, which is sometimes also known as Prousts Law. -
John Dalton
English chemist who proposed the Atomic Theory which stated that all matter was composed of small indivisible particles called atoms. These atoms possess unique characteristics and weight for different elembets. He also stated that three types of atoms exist: simple, compound, and complex. -
Crookes
Developed the Crookes tube and in it produced cathode rays for the first time. He also invented the radiometer and spinthariscope. -
Indivisible, solid sphere model
Democritus -
Becquerel
A French physicist who found that rays coming from a uranium ore affected a photographic plate like X-rays did. The rays were not from an external source and were more powerful than those from a sample of pure uranium. His experiment led to the discovery of natural radioactivity. -
Thomson
Cathode Ray Tube Experiment -
Curie
Studied and identified radioactive elements. -
Thomson
First to measure the electron. Developed the
plum-pudding model of the atom. Describes the atom as a
slightly positive sphere with small electrons inside. -
Robert Millikan
Discovered the charge of an electron with his oil drop
experiment. -
Ernest Rutherford
Atomic Atom -
Ruherford
Gold Foil Experiment -
Neils Bohr
A Danish physicist who stated that electrons could only orbit the nucleus in succesively larger orbits around the nucleus. The outer orbits could hold more electrons. The electrons in the outermost shell determine the properties of the atom. -
Henry Moseley
A British chemist, Henry Moseley studied under Rutherford and brilliantly developed the application of x-ray spectra to study atomic structure. Moseley's discoveries resulted in a more accurate positioning of elements in the periodic table. -
Erwin Schrodinger
Electron cloud -
Chadwick
Discovered neutrons. -
Democritus - 442 BC
Said the universe is made up of empty space and a nearly infinite number or invisible particles differing in arrangement, form, and position. He stated that all all matter is composed of indivisible atoms.
