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Period: to
Chemistry
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Lavoisier
provided the formula for the conservation of matter in chemical reactions, and also distinguished between an element and a compound. -
Couloumb
formulated the Coulomb's law, which states that that the force between two electrical charges is proportional to the product of the charges and inversely proportional to the square of the distance between them, one of the main forces involved in atomic reactions. -
John Dalton
formed the atomic theory, which states that all matter is composed of tiny, indestructible particles called atoms that are all alike and have the same atomic weight. -
Crookes
created the Crookes’ tube and demonstrated that cathode rays travel in straight lines and produce phosphorescence and heat when they strike certain materials. -
W.K. Roentgen
discovered x-rays while experimenting with cathode-ray tubes. -
Becquerel
discovered radioactivity when he investigated uranium and other radioactive substances. -
The Curies
discovered radium and polonium when they started to investigate radioactive substances -
J.J Thomson
- discovered the electron and developed the plum-pudding model of the atom.
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Max Planck
originated the quantum theory -
Albert Einstein
postulated that light was made up of different particles that, in addition to wavelike behavior, demonstrate certain properties unique to particles. He also brought forth the theory of relativity. -
Robert Milikan
found out the electric charge of the electron -
Ernest Rutherford
used the results of his gold-foil experiment to state that all the mass of an atom were in a small positively-charged ball at the center of the atom. -
Neils Bohr
stated that the electrons moved around the nucleus in successively large orbits. He also presented the Bohr atomic model which stated that atoms absorb or emit radiation only when the electrons abruptly jump between allowed, or stationary, states. -
Geiger
introduced the first detector of alpha particles and other radiations.