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John Dalton
He proposed the law of Multiple proportions. Which led to the atomic theory. He developed a system of symbols to represent atoms of different elements. He recognized the existence of elements, atoms and that compounds formed the union of these atoms. He also discovered colour blindness which he also suffered from. He found the 5% of men were colour blind and one tenth percent of women were colour blind. -
Marie Curie
She studied the chemical compounds which gave a result that the radiation did not depend on the compound. It actually depended on the amount of uranium or thorium. She concluded that the ability to radiate did not depend on where the atoms were arranged in a molecule. -
J.J Thomson
He discovered the electron. He found the negatively charged electron in the cathode ray tube. The electron was a component of all matter, he calculated the charge to mass ratio for the for the electron. He studied the positive rays in the cathode ray tube. He discovered the charge to mass ratio meant filling the tube with gas. -
Ernest Rutherford
He presented the nuclear atom as the result of the gold foil experiment. He said that the positive charge and all mass of the atom had a small volume inside the atom. Most of the volume of the atom was empty space. He thought that their was a third atomic particle which was the neutron. -
Henry Moseley
He discovered that the x-rays energy was being emitted by the elements. This increased a Linear form with each sequential element in the periodic table. He said that the relationship was a function of the positive charge of the nucleus. This meant that the periodic table had to be rearranged by using the atomic number instead of the atomic mass, this represented the progression of the element. This also left spaces for elements to be discovered. -
Francis Aston
He was first to see isotopes and find out there were 212 natural isotopes. He invented the Mass Spectograph, he found that there were three different types of Hydrogen atoms. He found that while most atoms have 1 mass number, the hydrogen atoms had 2 or 3. -
Niels Bohr
He developed the atom with the atomic nucleus at the centre, with electrons around it. He developed an understanding of the atomic structure and quantum mechanics. Quantum mechanics is when the energy jumps from one energy level to another. -
Erwin Schrodinger
He developed an atom by combining the equations for the behavior of waves with the de broglie equation to make a mathematical model. The electron is a wave and tries to describe the regions in space or orbital. The model shows the probability that an electron can be found. -
James Chadwick
James discovered the neutron. This discovery led to the discovery of fission and mainly the atomic bomb. Because of his discovery of neutrons it was possible to make elements heavier that uranium. -
Murray Gell-Mann
He discovered what makes up protons and neutrons, quarks. A quark is a point of energy and he discovered that protons and neautrons have three. There are two types of quarks, up ones and down ones. Protons have two up quarks and one down quark and neutrons have two down quarks and one up quark. These three quarks form the core of an atom.
