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Democritus
It is believed that the Greek Philosipher Democritus was born in the year 460 BCE. Democritus had a theory that only things that where real where atoms and the void. But different combinations of said atoms made different things, such as hot and cold or hard and soft. -
Antoine Lavoisier
Antoine Lavosier was born on the 26th of August, 1743 in Paris, France. Antoine discovered many of the early elements and created the first extensive list of them. He also discovered that although matter may change its shape or form, it's mass remains the same. Antoine is sometimes reffered to as the farther of modern chemistry. -
Dalton
John Dalton was born on the 6th of September 1766 in Cumbria, England and died July 27, 1844, In 1803 John Dalton discovered that there was a point where matter could be broken down no longer, he called these tiny particles atoms. -
Dmitri Mendeleev
Dmitri Mendaleev was born in Russia on the 8th of February, 1834. He went on to create The Periodic Table of Elements. He did it in such a way that even though some of the elements hadnt been discovered, he left a space for them and even predicted some of there properties. Three of these elements he predicted where discovered in his life time and fit almost perfectly into his table. -
Joseph John Thomson
Joseph John Thomson was born on December 18, 1856 in Manchester, England. He, through many experiments discovered that there where tiny, negatively charged particles. he explained them using a plumb pudding model, where the negatively charged particles (plumbs) where surrounded by the possotivly charged matter (pudding). -
Robert Millikan
Robert Millakan was born on the 22nd of March in the year of 1868 in the state of Illinois. Millikan is most noted for his discovery of the charge of an electron. -
Ernest Rutherford
Earnest Rutherford was born on the 30th of October in the year 1871. After researching and testing Thomsons Plumb Pudding Model of the atom, Rutherford discovered that instead of having on large area in which the protons, neutrons and electrons lie, the protons and neutrons are actually squashed up into a small nucleus in the center around which the electrons orbit. -
Fredrick Soddy
Frederick Soddy was born on the 2nd of September, 1877, in Sussex, England. In 1912, Soddy proposed that the same elements could have different number of neutrons in the nucleus, He called them isotopes. An example of this is Uranium 235 and Uranium 238, they are two different isotopes of the same element, Uranium. One having 235 protons and neutrons in it's nucleus and the other having 238 -
Niels Bohr
Niels Bohr was born on the 7th of October 1885 in Denmark. Bohr, while reaserching the Rutherford model, discovered that the electrons in the atom did not behave randomly but followed paths which we now call energy levels. -
Henry Moseley
Henry was born on the 23rd of November, 1887 in Dorset, England. Moseley updated the periodic table of elements with the addition of Technetium and Promethium by noticing their gaps in the periodic table. He also confirmed that atomic number is more important then atomic weight. -
James Chadwick
James Chadwick was born on the 20th of October, 1891 in Manchester, England. Chadwick proved the existence of neutrons (particle without an electrical charge) in the nucleus of an atom.
