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Period: 100 to
100 BC - 2000
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335
The Alchemists (Plato)
The Alchemists were Aristotle and Plato. Aristotle told everyone that the world was made of earth, air, water, and fire. Plato came up with the word element aroung 400 B.C. -
430
Democritus
Democritus was the first person to make a atom model. His model was the "Billard Ball" Model. Democritus' thery was that matter could not be divided into smaller and smaller peices forever because eventually thesmallest peice would me obtained. -
Robert Boyle
Boyle conducted lots of experiments which helped him with the discovery of the relationship between pressure and volume of gases. This resulted in the “Boyle-Mariotte Law” which istates that if the temperature is constant, the volume of gas is proportional to the pressure. The phrase “chemical analysis” was also made by Boyle. -
Lavoisier
The Law of Conservation of Mass states that matter can be changed from one form into another, mixtures can be separated or made, and pure substances can be decomposed, but the total amount of mass remains constant. -
John Dalton
Dalton preformed many experiments that led to the overall accepentance of atoms. HIs theory was that all elements were made up of atoms, and that all the atoms of the same element were the exaclty the same. -
Dmitri Mendeleev 1834-1907
Dmitri was known for formulating the Periodic Table of the chemical elements, he loved Chemistry and he wanted to find a better way of organizing it. -
J.J. Thomson
Thomson's model was called the "Plum Pudding" model. Thomson studied the passage of an electric current through a gas. during his studies, he concluded that a negarive charge came from within a atom and a particle smaller then an atom had to exist. -
Pierre and Marie Curie
Pierre and Marie Curie are best known for their study of radioactivity, which led to their discovery in 1898 of the elements radium and polonium. -
Albert Einstien
Albert had his theory of special relativity that determined that the laws of physics are the same for all non-accelerating observers, and he showed that the speed of light in a vacuum is the same no matter the speed that an observer travels -
Ernest Rutherford
Rutherford's experiment showed that if two things with the same charges (for example magnets) will repel each other due to having the same charges. -
Neils Bohr
Bohr helped us understand that electrons orbit around the nucleus. -
Henry Moseley
he discovered lots of thing including the atomic battery and that the the difference between elments was the number of protons each had. -
Electron Cloud
