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Democritus (460-370 BCE)*
Democritus, a Greek philosopher born around 460 BCE in Thrace, Greece, proposed many modern ideas on Atomic Theory that we still use today. Democritus believed that matter was not divisible and that matter could not be destroyed, created, or divided. The concept of the atom was first proposed by Democritus, a term we still use today in modern science. The pioneer of modern atomic theory died sometime around 370 BCE. -
Antoine Lavoisier
It took more than two millenia until new research was developed on atomic theory. Antoine Lavoisier was a French scientist born in 1743. Lavoisier denied the real existence of atoms and believed that light to be an element, two things that are incorrect. Lavoisier is famous for developing "The Law of Conservation of Mass." Lavoisier was beheaded in 1794 during the French revolution. -
John Dalton
John Dalton was an English chemist born in Cumberland England on September 6, 1766. Dalton was born colorblind, something he would deal with for the rest of his life. Dalton did his first work on gas laws, however, his most famous work came later when he proposed the first formal set of rules for matter. This became known as "Dalton's Atomic Theory." -
JJ Thomson
Joseph John Thomson was born on December 18th, 1856 in Manchester, England. JJ Thomson is most noted for his discovery of electrons. Thomson died on August 30th, 1940, and was buried in Westminster Abbey, close to Sir Isaac Newton. -
Robert Millikan
Robert Millikan was born in Illinois on March 12th, 1868. Millikan came from a midwest pioneer family; his family was one of the first to settle in the Illinois region. Following many years of education, Millikan conducted many experiments, finally concluding that the charge of a single electron and that its charge is constant with all electrons. Millikan also verified Einstein's 1905 photoelectric theory. Robert Millikan died December 19, 1953, in San Marino, California. -
Ernest Rutherford
Born in 1871, New Zealand scientist Ernest Rutherford was bound for success. Rutherford attented college at the age of 16. In his early work, Rutherford determined the concept of Radioactive half-life. Rutherford's most famous discovery came in 1911, when he split the atom, giving him the name "The father of nuclear physics." Due to living most his life in England and due to his discoveries in science, Rutherford was knighted by the Queen. He died on October 19, 1937, at the age of 66. -
Niels Bohr
Niels Bohr was a Danish scientist who made major contributions to modern atomic structure. Bohr, using Rutherford's theory, wrote a new theory stating that electrons revolve in specific orbits around the nucleus of an atom, and that such orbits determined the chemical properties of the individual atom. Following his research, World War Two broke out, forcing him to travel to Sweden for safety due to him having a Jewish mother. The Danish scientist died on November 18th, 1962. -
Erwin Schrodinger
On August 12th, 1887, in Vienna, Austria, the bright mind on Erwin Schrodinger was born. As a child, Schrodinger enjoyed painting, poetry and science. Schrodinger decided he wanted to persue a science related degree. As a scientist, his most well-known discovery was his view of electrons as continuous clouds and introduced "wave mechanics" as a math representation of the atom. -
James Chadwick
James Chadwick was born on October 20, 1891 in Cheshire England. Chadwick worked under Ernest Rutherford for some time at the University of Manchester. In 1932, Chadwick was awarded a Noble Prize for his discovery of the nuetron. James Chadwick, much like his teacher Ernest Rutherford, was kighted in 1945. Chadwick died July 24th, 1971. -
Louis de Broglie
Louis de Broglie was a French scientist and World War One veteran. De Broglie is credited for discovering the dual-nature relationship electrons had showing similarities with particles and waves. De Broglie died on March 19, 1987, at 94 years old. -
Werner Heisenburg
Werner Heisenburg was a German scientist born on December 5th, 1901. He played a key role in the evolution of quantum physics. Heisenburg stated that atoms are described by means of mathmatical models related to the frequencies of spectral lines. The famous German scientist also proposed the Principle of Indeterminancy. A Noble prize was awarded to him for the creation of quantum physics in 1932. Heisenburg died on February 1st, 1976. -
Aristotle (384-322 BCE)*
Another Greek philosopher that had a big impact on atomic theory was Aristotle. Arisitotle was born in 384 BCE. Aristotle was a student of Plato and later a teacher of Alexander the Great. The mighty Aristotle was known for rejecting any other philosophies besides his, deeming his to be the only correct philosophies. He did this with Democritus' ideas, rejecting the concept of the atom. Aristotle proposed the idea that all matter was made of earth, fire, air, and water. He died in 322 BCE.
