-
350
Aristole B.C.
Aristole was a scientist and a philosopher. He believed that everything was made up of five elements. The elements were fire, water. earth, wind, and ether. Ether was a heavenly material. Aristoles ideas were the most commonly accepted. People could see what he was saying and believed in him. -
460
Democritus B.C.
Democritus was the irst one to come up with the idea of a atom. He though atoms were small, hard particles. Also thought that they are made of one material and they came in different shapes and sizes. Atoms were always moving and they from different materials by joining together. Everyone thought he was crazy. -
Antoine Lavoisier
The most importat thing he foud was the conversation of mass. Matter can not be destroyed by a chemical reaction, even though it may change its appearance. At high speeds mass changes to energy.He was also one of the discoverer of oxygen, among other things. -
John Dalton
He was most famous for his pioneering work in the development of the modern atomic theory, and his research on color blindness. Dalton brought back the idea of Democritus. Also, he created a law of multiple proportions that states that when two elements combine to form more than one compound combination with a fixed amount of the other element will show a multiple reaction. -
Henri Becquerel
While examining uranium salts, Becquerel accidently discovered radioactivity. This discovery led him to investigate the emission of nuclear radiation. -
Marie & Pierre Curie
Marie Curie and her husband Pierre uranium and thorium and called their decay process radioactivity. they also discovered the radioactive elements polonium and radium. -
J.J. Thomson
J.J. Thompson researches and names electrons. He also out its mass to change ratio. Also, he creates his plum pudding model that an aton is a sphere of positively charged energy with negatively charged electrons embedded inside. Thomson was awarded novel prize in physics for the discovery of electrons, isotopes, inventing the mass spectrometer, and for his work on the conduction of electricity in gases. -
Robert Millikan
He made an oil drop experiment. Millikan was able to determine not only the charge of the electron, but also the mass of an electron. -
Ernest Rutherford
Ernest Rutherford was known as the father of nuclear physics. He drew up his model of the atom which suggested that the atom had a tiny, positive nucleus in his center. this was surrounded by electrons. He won a novel prize for his work. -
Neils Bohr
Neils Bohr considered the term of stationary orbits for the elaectrons and that there is more than one level of orbit. He also thought that when an electron moves between orbits, it emits a proton in a form of light. -
Henry Mosely
Henry Morsely discovers that an element contains a unique positive charhe in its nucleus. He called these particles protons. -
Max Planck
Max Planck discovered the quantum theory. He showed hat light must be emitted and absorbed in discrete amounts if it was to correctly describe observed phenomena. Quantum theory deals with the the particles that atoms are made of. -
Erwin Schrodinger
Erwin Schrodinger discovered molecular biology, the concept of negentropy and was most famous for the his mathematical formula used in quantum mechanics. (an equation which could describe energy waves) His research led him winning the Nobel Prize in Physics. -
Werner Heisenberg
Werner Heisenberg proposed the Principal of Indeterminancy which states you can not know both the position and velocity of a particle. -
James Chadwick
James Chadwick was one of the most influential researchers in the field of atomic theory. He used alpha particles to dicover a neutral atomic particle with a mass similar to the proton. This was named the neutron. His discovery led to nuclear fission and the atomic bomb.
