-
The Alchemists broke down the composition of the 4 basic elements. They later created a scientific process which would allow for the later discovery of the atom. -
Democritus found the atom and came up with the name. He also stated that everything is made up of tiny bits. -
Plato introduced the atomic theory in which ideal geometric forms serve as atoms according to which atoms broke down mathematically into triangles. -
Robert Boyle discovered that atoms must exist based on the relationship between pressure and gas. -
Antone Lavoisier came up with The Law of Conservation. This law stated that matter is unable to be made or destroyed. -
John Dalton created "Dalton's Atomic Theory". His theory stated that everything is composed of atoms which are invisible building blocks of matter and cannot be destroyed. He also discovered that all atoms of an element are identical. -
The Billiard Ball Model was created by John Dalton. Dalton thought that atoms were the smallest particles of matter, and he envisioned them as small, hard spheres like a billiard ball. -
Amedeo Avogadro formulated the gas law known as the Avogadro Law which states that all gases, at the same temperature and pressure, have the same number of molecules per unit of volume. -
Dmitri Mendeleev found that when all known chemical elements were arranged in order of increasing atomic weight the resulting table showed a recurring pattern of properties within groups of elements. -
The Plum Pudding Model created by J.J. Thomson depicts the electrons as negatively-charged particles embedded in a sea of positive charge. -
JJ Thomson discovered the electron and how it is a negatively charged particle. This was part of the Thomson Atomic Theory. -
Pierre and Marie Currie discovered and isolated radium, a new element which spontaneously disintegrated into other elements. This proved that the atoms of one element at least were not indivisible. -
Albert Einstein was able to fully prove that atoms exist. With that, he also proved that electrons could leave metal through usage of light. -
Ernest Rutherford created a model describing the structure of an atom. This was called the Rutherford Model. It showed the atom as a tiny, dense positively charged core with negative constituents circulating at a distance. -
Robert Millikan discovered that there is a fundamental electric charge which directly relates to the charge of an electron. -
Neils Bohr proposed a model of the atom in which the electron was able to occupy only certain orbits around the nucleus. -
Henry G.J. Mosely discovered that the major properties of an element are determined by the atomic number not the atomic weight. He also proved the relationship between the atomic number and the charge of an atoms nucleus. -
The Solar System Model created by Neils Bohr, explained how electrons can have stable orbits around the nucleus. -
Werner Heisenberg contributed to the Atomic Theory by formulating quantum mechanics in terms of matrices. This eventually led to discovering that a particle's position and momentum cannot both be exactly known. -
Erwin Schrodinger showed that the quantization of the hydrogen atoms energy levels could be calculated from the Schrodinger equation. -
The Electron Cloud Model created by Erwin Schrodinger was used as a way to help visualize the most probable positions of an electron inside of an atom. -
James Chadwich discovered the neutron. His findings were pivotal to the discovery of nuclear fission and eventually led to the development of the atomic bomb.