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Atomic Theory
Chemist John Dalton created his atomic theory in 1803. According to Dalton's theory, a certain number of atoms of one substance always combined with a certain number of atoms of another substance in forming a compound. -
The Law of Definite Proportions
The law of definite proportions contributed to, and was placed on a firm theoretical basis by, the atomic theory that John Dalton promoted beginning in 1803. Joseph Proust found this out. -
The Law of Combing Volumes
the Italian chemist Amedeo Avogadro (1776–1856) relate to the work of two of his contemporaries, Joseph Louis Gay-Lussac and John Dalton. Gay-Lussac’s law of combining volumes stated that when two gases react, the volumes of the reactants and products -
Dimitri Mendeleev's cotribution
Dmitri Mendeleev revolutionized our understanding of the properties of atoms and created a table that probably changed every chemistry classroom in the world. -
Marie Curie's Discovery
In July 1898, the Curies announced the discovery of a new chemical element, polonium. At the end of the year, they announced the discovery of another, radium. The Curies, along with Becquerel, were awarded the Nobel Prize for Physics in 1903. -
Ernest Rutherford's Contribution
He thought the nuclear structure of the atom. Experiments done in his lab showed that when alpha particles are fired into gas atoms. -
Joseph John Thompson's Contribution
In 1904 Thomson suggested a model of the atom as a sphere of positive matter which had electrons that are positioned by electrostatic forces. His efforts to estimate the number of electrons in an atom from measurements of the scattering of light. -
Hans Geiger's Discovery
After the huge discovery of the nucleus, Geiger went on to work on the "Geiger formula" which determined the velocities of particles in 1910. -
Niels Bohr's Contribution
In 1913, Bohr published a theory about the structure of the atom created as basically an extension on an earlier theory of Rutherford's. Rutherford had shown that the atom consisted of a positively charged nucleus, with negatively charged electrons in orbit around it. Bohr expanded upon this theory by proposing that electrons. -
Enrico Fermi's Discovery and Creation
on December 2, 1942, it produced the first controlled, self-sustaining nuclear chain reaction. Fermi had succeeded in taking one of the first steps to making an atomic bomb.
