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Period: 400 BCE to
the beginning of chemistry
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384 BCE
300
Famous Greek philosopher, Aristotle, disagrees with Democritus. He discloses Democritus's idea and proposes a new conept. He states that everything is composed of four basic elements: earth, air, water, fire. Being a highly revered philosopher, people chose to agree with Aristotle and Demoritus's idea was lost. -
Sir Robert Boyle (01/25/1627 - 12/311691)
Founder of modern Chemistry. Created basic gas laws and formed Boyle's law. He also stated that small particles form to create molecules. He also staed the difference between compounds and mixtures. -
Benjamin Franklin (01/06/1705 – 04/17/1790)
He proved that lightning was a form of electricity. -
Joseph Priestley (03/24/1733 – 02/06/1804)
He discovered gases such as; carbon monoxide, nitrous oxide, and oxygen. -
Dmitri Mendeleev 02/08/1834 - 02/02/1907)
He found periodicity of elements. He compilied the first Periodic Table with 7 groups. -
Joseph J. Thomson (12/18/1856 - 08/30/1944)
Thomson was well known for his work with cathode rays. He also discovered the electorn. He constucted one of the first models of an atom -
Marie Curie (11/07/1867 - 07/04/1934)
They were well known for their research on radioactivity. They discovered Radium and Polonium. They won the nobel prize in 1903 with Henri Becquerel. She was the first woman to win a nobel prize. She is also the only person to win two Nobel Prizes in two different subjects. -
Ernest Rutherford (08/30/1871 - 10/19/1937)
He is known as the "father of nuclear physics". He stated that the atom is mostly empty space with a central nuclues. He is also credited with splitting the first atom. He also created the Rutherford model of an atom. -
Niels Bohr (10/07/1885 – 11/18/1962)
He aided James Chadwick in understanding the atomic structure. He then created a new atomic model, the Bohr model. -
Willard LIbby (12/17/1908 – 09/08/1980)
He developed carbon dating using carbon-14.
