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Period: 460 BCE to 370 BCE
Democritus
Democritus was an Ancient Greek philosopher born 460 BCE and died 370 BCE. He stated that all things were made up of atoms. This was a theory that Aristotle disagreed with but it was proven that Democritus was right. Fun Fact:
He was often know as the “laughing professor “ because he was always cheerful at work. -
Period: to
Antoine Lavoisier
Andrew Lavoisier was born in 1743 in Paris, France and died in 1794. One of his biggest contributions were the naming of Carbon, Hydrogen, and Oxygen. One experiment he conducted put a diamond in a jar and used a magnifying glass to focus the sun on the diamond. The diamond burned leaving a gas behind the same as charcoal, leading him to state that a diamond and charcoal are different forms of the same element, Carbon. Fun Fact:
He died by guillotine after being labeled a traitor in 1794. -
Period: to
John Dalton
John Dalton was born in 1766 in England, UK and died in 1844. He is best known for Dalton’s Law which states that “the pressure of a mixture of gases is equal to the sum of the partial pressure that each individual gas would exert by itself at the same volume and temp.” To prove this theory he would conduct series of experiments on gases. Fun Fact:
He was a Quaker. -
Period: to
J. J. Thomson
J. J. Thomson was born in 1856 in England, Uk and died in 1940. His most important discovery was the electron, the first subatomic particle. The experiment that led to the discovery of the electron was a cathode ray tube experiment. When the cathode rays travelled through air he was surprised because he noticed that the cathode ray particles were smaller than atoms, which lead him to discover the subatomic particle, electron. Fun Fact:
He was awarded the Nobel Prize for his discovery (electron) -
Period: to
Max Planck
Max Planck was born in 1858 in Germany and died in 1947. He was best known for discovering the quantum of action which laid the foundation for the quantum theory. Through experiments he was able to demonstrate that energy can exhibit characteristics of physical matter. Fun Fact:
He was a great musician. -
Period: to
Marie Curie
Marie Curie was born in 1867 in Poland and died in 1934. She was best know for discovering the elements polonium and radium. The experiment she used involved successfully isolating radioactive radium salts from the mineral pitchblende. Fun Fact:
She had to seek out alternate education for women. -
Period: to
Robert Millikan
Robert Millikan was born in 1868 in Illinois and died in 1953. He was best know for discovering the charge of the electron using the oil-drop experiment. In the oil drop experiment, Millikan charged drops of oil between two electrodes and balanced the gravitational force to prove his theory. Fun Fact:
He decided to research the charge of an electron to increase his academic rank. -
Period: to
Ernest Rutherford
Ernest Rutherford was born in 1871 in New Zealand and died in 1937. His biggest contribution to the Atomic Theory was that he found that the atom consists of mostly empty space with most of its mass in one spot, the central positively charged nucleus. He made this discovery after conducting his widely know gold foil experiment which showed that the atom was tiny with a heavy nucleus. Fun Fact:
He was fourth of twelve children. -
Period: to
Albert Einstein
Albert Einstein was born in 1879 in Germany and died in 1955. He was best known for devising his theory of relativity, which changed our perspective on space, time, gravity, and the universe. Fun Fact:
He married his first cousin. -
Period: to
Niels Bohr
Niels Bohr was born in 1885 in Denmark and died in 1962. He was known for the Bohr Model, that showed that electrons should move around the nucleus in specified orbits. Fun Fact:
He won a Nobel Prize at the same time as Albert Einstein. -
Period: to
Erwin Schrodinger
Erwin Schrodinger was born in 1887 in Austria and died 1961. He was known for creating a wave equation that calculated the energy levels of electrons in atoms. Fun Fact:
A moon crater is named after him. -
Period: to
James Chadwick
James Chadwick was born in 1891 in the UK and died in 1974. He was best know for discovering the neutron. He discovered it using scattered data to calculate the mass of the neutron. Fun Fact:
He was put into a prison camp in Germany when WW1 began and remained trapped until the war was over. -
Period: to
Louis De Broglie
Louis De Broglie was born in 1892 in France and died in 1987. He was best known for his work on quantum theory and discovering the wave nature of electrons. Fun Fact:
His first degree was in history but he earned other degrees in math and physics. -
Period: to
Werner Heisenberg
Werner Heisenberg was born in 1901 in Germany and died in 1976. He was known for formulating quantum mechanics in terms of matrices. Fun Fact:
He was born in Wurzburg, Germany.