-
Isaac Newton
Sir Isaac Newton was the first to formulate the idea that absolutely everything is made up of these small, massy, and solid particles. He stated that all these particles are "help together by attractions", which we know today are forces. Newton was in fact the first person to recognize and acknowledge the existence of atoms which layed the groundwork for many after him to come. Newton did not use any experiments, as all he had was a theory, the only evidence he provided was religious. -
Charles-Augustin de Coulomb
Coulomb devised a crcuial cog in the atomic theory, and it is now reknowned by physicists as "Coulombs Law". Interested in the attractive and repulsive forces of different charged particles, Coulomb used a torsion spring he made himself to study it, He concluded "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" which is a main force in atomic reactions. -
John Dalton
Whilst studying Meteorolgy, Dalton came to the conclusion that the forces that result in pressure acted only between atoms of the same kind, although they differed in complexity and weight. Using percentage composition of a few different compounds, Dalton attempted to determine the atomic structure of different compounds. Dalton concluded that all matter is made from atoms, and that these atoms cannot be created nor destroyed, -
JJ Thompson
In 1897, Thompson made a breakthrough discovery. Inside a cathode tube, Thompson implemented two plates parallel to each other and a cathode ray passed within a peephole in the tube. The ray travelled in a straight line, illuminating the sides of the tube. Thompson procceeded to introduce an electric field, and the ray deflected onto a different plate, succesfully discovering the electron particle. -
The Curies
The Curies, Marie and Pierre, won a nobel prize for their contributions towards atomic theory. They discovered radioactive metals such as Polonium and Radium. After Marie realized that Uranium and Thorium compounds emitted stronger radiation that Uranium, her and her husband Pierre chemically extracted radioactie metals from Pitchblende ore. On top of that, she won another noble prize for discovering that some x-rays can be used to kill tumors. -
Ernest Rutherford
In 1911, Ernest Rutherford discovered that most of the atom was composed of 'empty space' and that there is a postive nucleus in the middle, surrounded by negatively orbiting electrons. Rutherford conducted his reknowned gold foil experiment, which involved firing radioactive particles through thin metals (gold) and viewing them on a scintillator. Although most of the particles passed through, only 1 in 8000 of them were deflected, leading Rutherford to believe that the atom is filled with 'ES' -
Niels Henrik David Bohr
Neils Bohr is one of the biggest names in atomic theory. Bohr used some of Rutherfords works on the atom and some of Plancks Quantum Theory to devise the atomic structure. Bohr's model of the atom was actually 1/10,000 the size of that of other scientists. That in itself was a contribution because it brought the size of the atom into perspective. Also, Bohr concluded that outer orbits of the atom can hold more electrons than the inner orbits. -
Arnold Sommerfeld
In the early 20th century, Arnold contributed to Bohr's atomic model by stating that there were elliptical paths for electrons within the atom. He also discovered that this orbit can change in the presence of a magnetic field. Sommerfeld stated the the number of possible orbit positions is 2*l+l and that each different position is in fact a different energy. He contributed to the atomic model by stating that the spectral line is made up of 2 lines very close to each other; "Sommerfeld Model" -
Werner Heisenberg
Heisenberg is reknowned for studying behavior of atoms and also sub atomic particles through mathermatics. He attempted to make sense of the patterns of electrons. Through the usage of quantum mechanics, Heisenberg contributed by discovering how to determine the number of electrons in an atom by a pattern of movements. Also, he discovered that all electrons that contain photons will then change momentum and physics. -
Erwin Schrödinger
In 1926, Erwin Shrodinger took the Bohr model of the atom and applied several mathematical equations to it. He did this to determine the likelihood of finding an electron in a specific position. This model of the atom was used to determine the odds of finding an electron at a certain place, and was dubbed the "Quantum Mechanical Model". Without Shrodinger, scientists would have no grasp on the idea of sub-energy levels. -
James Chadwick
Chadwick, while studying atomic disintegration, realized that the atomic number was always less then the atomic mass. Since electrons are pretty much mass-less, he hypothesized the existence of another neuron within the atom, that would work parallel or perpendicular to the electron, Whilst tracking particle radiation, he discovered the existence of the Neutron, and that it was approximately 0.1 % heavier than its counterpart, the proton. -
Linus Pauling
Linus Pauling is name known to chemists, physicists, and mathemeticians alike. He combined quantum theory with chemistry to study the structure of atoms and molecules. Paulings breakthrough came when he discovered how to use "The Schrödinger Equation" in the context of compounds such as benzene.
