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Democritus
He hypothesized that all matter (plus space and time) is composed of tiny indestructible units, called atoms. -
antoine Lavoisier
He found that mass is conserved in a chemical reaction. The total mass of the products of a chemical reaction is always the same as the total mass of the starting materials consumed in the reaction. His results led to one of the fundamental laws of chemical behavior: the law of conservation of matter. -
John Dalton
His theory is all matter is made of atoms, all atoms of a given element are indentical in mass and properties, compounds are formed by a combination of two or more different kids of atoms, and a chemical reaction is a rearrangement of atoms. -
joseph louis proust
He first published his Law of Definite Proportions (or Law of Constant Composition).This law states that a compound is composed of exact proportions of elements by mass regardless of how the compound was created -
Micheal Faraday
Faraday discovered the two laws of electrochemistry: the amount of chemical change or decomposition is exactly proportional to the quantity of electricity that passes in solution; and the amounts of different substances deposited or dissolved by the same quantity of electricity are proportional to their chemical equivalent weights. -
Lisa Meitner
She collaborated with Otto Hahn in the discovery of neuclear fission and gave the first theoretical explanation of the fission process. -
Otto Hahn
Discovery of nuclear fission -
Niels Bohr
He was the first to discover that electrons travel in seperate orbits around the nucleus and that the numner of electrons in the outer orbit determines the properties of an element -
Erwin Schrodinger
The Schrodinger Equation is "the wave equation of non relativistic quantum mechanics". He showed, through math, that waves can be used to describe electrons in atoms. -
Henri Becquerel
While studying the effect of x-rays on photographic film, he discovered some chemicals spontaneously decompose and give off very pentrating rays. Discovery of radioactivity. -
J.J. Thomson
His theory was all atoms were made up of small particles, which led him to the discovery of electrons. -
Marie and Pierre Curie
They are best known for their pioneering work in the study of radioactivity, which led to their discovery in 1898 of the elements radium and polonium. -
Albert Einstein
Creates special and general theories of relativity, and hypothesizes about the particle nature of light. This was the basis of nuclear energy. -
Robert Milikan
He determined the unit charge of the electron with his oil drop experiment. Thus allowing for the calculation of the mass of the electron and the positively charged atoms. -
Glenn T. Seaborg
Identified almost ten transuranium elements. -
Ernest Rutherford
Rutherford proposed the existence of the neutron. -
Louis DeBroglie
He gained worldwide acclaim for his groundbreaking work on quantum theory. He discovered the wave nature of electrons and suggested that all matter have wave properties. -
James Chadwick
He discovered the neutron -
Max Planck
Originated the Quantum theory. This theory revolutionized our understanding of atomic and subatomic processes, -
Aristotle
He thought that all materials on Earth were not made of atoms, but of the four elements, Earth, Fire, Water, and Air.
