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300
Aristotle (384 BCE - 322 BCE)
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. -
400
Democritus (400 BCE - 370 BCE)
Greek philosipher, Democritus, develops the of atoms. He suggests that all things can be broken up into smaller particles until it reaches it's fundamental unit. He titled this unit as "atomus", which meant indivisible. -
Period: 400 to
Chemistry in History
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Alchemists (~1000 - 1650)
Alchemist were seen as the earliest chemists. They tried to develop a way to turn average stones and metals into more precious ones like gold. In doing so, they created various chemicals and medicines. During their time, they never accomplished thier goal. Most discontinued the study and began to work with other chemicals. -
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. -
John Dalton (08/06/1766 - 06/27/1884)
John dalton proposed the Atomic Theory. Dalton's atomic theory had five main focal points. It stated that: 1. elements are composed of extremy small particles called atoms. 2. all atoms in an element are exactly the same. 3. atoms can't be created, divided or destroyed. 4. different atoms combine to form compounds in whole number ratios. 5. atoms are seperated, rearranged, or combined in chemical reactions. -
Amedeo Avogadro (09/09/1776 – 07/09/1856)
He stated that Atoms react in fixed proportions. He Atoms constantly move. He also stated that atoms form to create molecules. He is also known for Avogadro"s number. -
Robert Brown (12/21/1773 - 06/10/1858)
He discovered Brownian motion. -
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. -
Pierre Curie (05/15/1859 – 04/19/906)
He worked with his wife, Marie.They were well known for their research on radioactivity. They discovered Radium and Polonium. They won the nobel prize in 1903 with Henri Becquerel. -
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. -
Henri Becquerel (12/15/1852 - 08/25/1908)
He discovered radioactivity of Uranium. He worked with the Curies and won a Nobel Prize. -
Albert Einstein (03/14/1879 – 04/18/1955)
He created the theory of relativity. He created the equation e=mc^2. it explain the realtion between mass and energy. It shows how much energy a substance can give off. -
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. -
James Chadwick (10/20/1891 – 07/24/1974)
He discovered the neutron. -
Willard LIbby (12/17/1908 – 09/08/1980)
He developed carbon dating using carbon-14. -
Electron Cloud Probability
It describes the motion of electrons around the nucleus of an atom. Because electrons do not move in a fixed pattern, it is hard to track their location. So, we use a special model to describe their motion. it is known as the Electron Cloud Model. -
Dmitri Mendeleev 02/08/1834 - 02/02/1907)
He found periodicity of elements. He compilied the first Periodic Table with 7 groups.
