An Atomic Timeline

Joseph Proust

Mar 8, 1793

Joseph was a French chemist who proved that the relative quantities of any given pure chemical compound’s constituent elements remain the same, no matter how much of the compound’s source. This is known as Proust’s law (law of definite proportions( in 1793, and it is the principle of analytical chemistry.
(born Sept. 26, 1754, Angers, France—died July 5, 1826, Angers)

John Dalton

Mar 8, 1793

John Dalton came up with the theory that matter consists of indivisible particles called atoms and that atoms of a given element are all identical and can neither be created nor destroyed. Compounds are formed by combination of atoms in simple ratios to give compound atoms (molecules). The theory was the basis of modern chemistry. (Born: September 6, 1766, CockermouthDied: July 27, 1844, Manchester)

Amedeo Avogado

Mar 8, 1811

Amedeo Avogadro
In 1811 Amedeo stated that equal amounts of gases at the same temperature and pressure contain equal numbers of molecules. From this it continued that relative molecular weights of any two gases are the same as the densities of the two gases under the same conditions of temperature and pressure. Avogadro also stated that simple gases were not formed of solitary atoms but were instead compound molecules of two or more atoms.
(Born: August 9, 1776, Turin, Died: July 9, 1856,

Dmitri Mendeleev

Mar 8, 1869

Dmitri was a Russian chemist and inventor. In 1869 He created the first version of the periodic table of elements, and used it to predict the properties of elements yet to be discovered. Dmitri Mendeleev (Born: February 8 1834, Died – February 2 1907)

Joseph John Thompson a.k.a "JJ Thompson"

Mar 8, 1897

In 1897 JJ suggested a model of the atom as a sphere of positive matter in which electrons are positioned by electronic forces. His effort to estimate the number of electrons in an atom from measurements of light, X, beta, and gamma rays invented the research trajectory.
(Born: December 18, 1856, Cheetham HillDied: August 30, 1940, Cambridge)

Marie Curie

Mar 8, 1898

In 1898 Marie Discovered different ways for saving radioactive isotopes, and the discovery of two elements, polonium and radium. In her direction, the world's first studies were conducted into the treatment of neoplasms, using radioactive isotopes. Marie Curie Born: (November 7, 1867, Warsaw -Died: July 4, 1934, Sancellemoz)

Ernest Rutherford

Mar 8, 1900

In the early 1900's Ernest discovered the concept of radioactive life, proved that radioactivity involved the transition of one chemical element to another, and also identified and named alpha and beta radiation. (Born: August 30, 1871, Brightwater - Died: October 19, 1937, Cambridge)

Hans Geiger

Mar 8, 1912

In 1912 Hans built the first version of his particle counter and used it and other radiation detectors in experiments that led to the address of the alpha particle as the nucleus of the helium atom.
(Born: September 30, 1882, Neustadt an der Weinstraße Died: September 24, 1945, Potsdam)

Niels Bohr

Mar 8, 1913

Bohr developed the "Bohr model" in 1913 of the atom with the nucleus at the center and electrons in orbit around it, which he compared to the planets orbiting the Sun. He worked on the idea in mechanics that electrons move from one energy level to another in small steps, not continuously.
Niels Henrik David Bohr (Born: October 7, 1885, Copenhagen- Died: November 18, 1962, Copenhagen)

Enrico Fermi

Dec 8, 1942

In 1983 Enrico Developed the mathematical statistics required to clarify a large class of subatomic phenomena, and explored nuclear transformations caused by neutrons, and directed the first controlled chain reaction. Enrico Fermi (Born: September 29, 1901, Rome- Died: November 28, 1954, Chicago)I