-
Issac Newton
Atoms could move and cause things to move as well.
Newton's Laws
An object in motion tends to stay in motion.
The change in velocity which an object moves is proportional to the magnitude of the force applied to the object and inversely proportional to the mass of the object.
For every action there is an equal and opposite reaction. -
Joseph Proust
Observed that specific substances always contain elements in the same ratio by mass. This principle is known as the Law of Definite Proportions -
Antoine Lavoisier
Found that when a chemical change occurreed in a closed system, the mass after a chemical change equals the mass before the change -
John Dalton
Dalton used the Law of definite Proportions and the Law of multiple protions to answer his hypothesis. -
Amadeo Avogadro
He stated that equal volumes of gases, under the same conditions, have the same number of molecules. -
J.J. Thompson
He is credited with the discovery of the electron and the proton, and for producing the first experimental evidence for the existence of isotopes. -
Sir William Crookes
Discovered that the cathode rays travel in straight lines from the cathode
It also cause glass to glow.
It impart a negative charge to objects they strike -
Henri Becquerel
Found that matter containing uranium exposes sealed photographic film. -
Max Planck
He developed the Quantum theory. Discovering quanta had changed the idea of physics since it showed that other ideas about radiation and energy were wrong. -
Hantaro Nagaoka
He was the first scientist to present a Saturnian model of an atom. The modal displayed a nucleus that had electrons ‘orbiting’ it and a positive electric charge . -
Robert Millikan
He worked on an oil-drop experiment which was used to measure charges on an electron. We can now measure the charge of a single electron from his experiment. -
Henry Moseley
He found a relationship between an element’s length and its atomic number.
Before this was discovered, the atomic numbers were just the element’s atomic weight -
Niels Henrik David Bohr
He investigated the atom’s structure and the radiation that is sent out from them. We now have more knowledge about the atom's structure and about the radiation. -
James Chadwick
He made a discovery in the domain of Nuclear Science
He proved the existance of neutrons. From his experiment, we are now able to break up Uranium 235 and create atomic bombs -
Ernest Rutherford
He made the Rutherford model which stated that a very small positively charged nucleus was orbited by electrons.
