-
370
Democritus (460 BC to 370 BC)
He said that everything had to come from everything and that matter is the combination and recombination of bits called atoms that are invisible, but can attach to other atoms to make up materials. Their solidness depends of the shapes of the atoms and the atoms will always have infinite size, shape, firmness and be completely solid. -
Antoine Lavoiser (1743-1794)
He had gone to college when he was 11 and he originally wanted to get a law degree, but then his interest in chemistry took control. He started doing chemistry analysis at the age of 25 and worked in the laboratory everyday (he worked with framing). -
John Dalton (1766-1844)
He made it clear that the atom was a chemical object. He also made the atomic theory:
All matter is made of atoms; atoms are indivisible and indestructive.
All atoms of a given element are identicle in mass and properites.
Compounds are formed by a combination of 2 or more different kinds of atoms.
A chemical reaction is a rearrangment of atoms.
His theory became the theoretical foundation in chemistry. -
Dmitri Mendeleev (1834-1907)
He studied science in St. Petersburg and graduated in 1856. What he is known for how he arranged the 63 elements into a Periodic Table by their atomic mass in 1869:
The first table was by ascending order of weight and simiarity or properities.
He predicted new atoms.
He left space for the unknow elements. -
Eugen Goldstein (1850-1930)
He discovered the canal rays in 1886 and that they were positively charged protons:
The produced a redish light at top of tube and green color when electrons hit sides of tube.
This led to the discovery of the proton. -
J.J Thomson (1856-1940)
He went to college at cambridge and started his research in cathode rays in 1894 that led to the discovery of the electron. He also won the Nobel Prize for his works in Physics. He discovered that all matter was made up of particles much smaller than atoms (electrons). -
Ernest Rutherford (1871-1937)
"Lord Rutherford" was a British physicist that is now known as the father of nuclear physics. He was awarded the Nobel Prize in chemistry in 1908 for his discovery of the concept of radioactive half-life. This discovery proved that radioactivity involved the transmutation of one chemical element to another. When experimenting with gold foil, he discovered that the nucleus is small, dense, and positively charged. James Chadwick discovered the neutron under his leadership in 1932. -
Henry Moseley (1887-1915)
He was an english physicist that justified the physical laws of the previous empirical and chemical concept of the atomic number. He created an x-ray spectra law. What he is most receognized for is sorting the chemical elements of the periodic table into a logical order based on physics. Moseley also provided the first experimental evidence of Niels Bohr's theory. Unfortunantly, he died fighting in WW1. -
Max Planck (1858-1947)
He originated quantum theory. He also had won the Nobel Prize in 1918 for his works in Physics. His theory revoluthionized our understanding of the atomic and subatomic processes. Enstein and him thought that their theories worked well together, since Enstein´s had to do with relative space. Both of their theories affected humankind and everyday life. -
Niels Bohr (1887-1962)
He was a danish physicist that received the Nobel Prize in physics for his foundational contributions to the understanding of the atomic structure and quantum theory. He also developed the Bohr model of the atom and conceived the principle of complementarity. After his discoveries, Bohr opened up the Institute of Theoretical Physics at the University of Copenhagen. -
Robert Millikan (1868-1953)
He was an American experimental physicist that won the Nobel Prize in 1923 for his measurement of elementary electric charge and for his work on the photoelectric effect. He determined that the mass of an electron is 9.11x10-28g, which is very very small. He started experimenting with charged water droplets in an electric field and later used charded oil drops to prove his hypothesis. -
Werner Heisenberg (1901-1976)
He was a german theoretical physicist that was one of the key pioneers of quantum mechanics. He won the Nobel Prize in physics in 1932 for his creation of quantum mechanics. -
James Chadwick (1891-1974)
Chadwick discovered the neuron. He found that the neuron existed inside of an atom's nucleus along with protons. He also discovered that a neutron has the same mass as a proton. In 1932, James Chadwick was awarded the Nobel Prize in physics for his work. -
Erwin Schrodinger (1887-1961)
He was an austrian physicist that developed many fundamental results in the field of quantum theory. He formulated the wave equation and proposed the original interpretation of the physical meaning of wave function. He won the Nobel Prize in physics in 1933.
