-
Period: 460 BCE to 370 BCE
Democritus
democritus was born in greece and was a rival of aristotle and was the first person to develop an atomic theory, saying everything was made of tiny particles that were never destroyed, just changed and moved. -
Period: 400 BCE to 300 BCE
Aristotle
born in present-day Greece. he proposed the variable atom theory with 2 pairs of alternates hot-cold, and wet-dry. he used these to explain the 4 elements earth (cold and dry), air (cold and wet), fire (hot and dry), and water (cold and wet) -
Period: 721 to 815
Abu Musa Jabir ibn Hayyan
born in modern-day Iran to a pharmacist. He has been dubbed the father of modern chemistry and developed instruments for measurements accurate to 1/6 of a gram. -
Period: 1200 to 1280
Albertus Magnus
St. Albertus Magnus was a German scientist and philosopher. he made the study of nature a ligitimate science in the christian church and was the only scholar of his age to be called a great -
1439
printing press
The printing press was used to print texts at a much more rapid pace than any human could do by using blocks and ink to print entire pages at a time. It was invented by Johannes Gutenberg with its first mention being in a lawsuit over the construction of one for Gutenberg and his colleagues. The printing press allowed knowledge to be spread much faster now that books could be printed at a much faster pace than before -
Period: to
Robert Boyle
born in Ireland. moved to Oxford in the 1650s and worked with Robert Hooke on developing the air pump or vacuum tube. He also discovered Boyles law relating gas volume to pressure. In 1660 he formed the royal society with 11 other scientists -
Period: to
Henry Cavendish
Henry Cavendish was an english physicist and chemist who researched with great precision the composition of atmospheric air, the properties of gasses, the synthesis of water, adn the laws of electrical attraction and repulsion -
Period: to
Antoine Lavoisier
born in France Lavoisier proved the conservation of mass by weighing the end result of all the chemical reactions he studied. french chemistry students are still taught the conservation of mass as Lavoisier's law. he also coauthored the modern system for naming new elements. -
Period: to
Amedeo Avagadro
Avagadro was an Italian mathematical physicist who discovered what is now known as Avogadro's law that under controlled pressures and temperatures equal volumes of gas will have equal numbers of molecules. -
Period: to
Dmitri Mendeleev
Mendeleev was a Russian born chemist who taught at St Petersburg technical institute. he needed a more accurate textbook for organic chemistry and while writing his own he discovered similarities between elements. this led to his formulation of the periodic law and later the periodic table of elements, the same one that is still used today -
Period: to
William Ramsay
William Ramsay was a British chemist who discovered neon, argon, krypton, and xenon along with the conclusion that they were part of a group of elements now known as the noble gasses. he recieved the 1904 nobel prize in chemistry for his achievements -
Period: to
JJ Thomson
born in england thompson is credited with discovering the electron. in 1887 thompson concluded that all matter is made of the same particle less massive than the atoms that they form. -
Period: to
John Dalton
he was born in england to a quaker family. In the early days of his career, he identified red-green color blindness. In 1803 he developed the law of partial pressures, and around the same time put forward his theory of the behavior of atoms in terms of atomic weight. He also said different elements could be differentiated by their weight and was the first to put forward the theory of conservation of matter. he later developed the first version of the periodic table with all the known elements -
Period: to
Marie Curie
Marie Curie was a french chemist and physicist and the first woman to win a nobel prize and the only person to win it in 2 different fields. the award was for the discovery of 2 new elements ,polonium and radium, and the discovery of radioactivity -
Period: to
Ernest Rutherford
born in New Zealand Rutherford was a physicist and proposed the planetary atomic model with most of the mass concentrated in the central nucleus with electrons circulating at some distance from the center the nucleus was thought to be small and dense to explain the scattering of alpha particles from gold in rutherfords experiments. he concluded that atoms were largely empty space because many of the alpha particles that he shot at the gold foil passed through undisturbed and a few got deflected -
Period: to
Lise Meitner
born in Austria, Lise was a nuclear physicist who along with Otto Hahn and Fritz Strassman discovered fission of uranium by neutron bombardment in 1966 -
Period: to
Neils Bohr
Bohr was a Danish physicist famous for applying the quantum concept to his model of an atom. the previous model was the rutherford model that, according to classic physics, would be unstable. The Bohr model had electrons orbiting at set distances from the nucleus at specific energy levels. -
Period: to
Erwin Schrodinger
Schrodinger was an Austrian physicist and scholar who is most famous for his thought experiments such as Schrodinger's cat but won the 1933 Nobel prize in physics for his electron wave equation. -
Period: to
James Chadwick
born in England in the late 1800s. He graduated from Victoria University in Manchester in 1911. In 1932 he discovered the neutron through beryllium disintegration. In 1943 he was selected as the leader of the British effort in the manhattan project to develop the atomic bomb. -
Period: to
louis de Broglie
louis de Broglie was a French physicist best known for his work on the quantum theory and the wave nature of electrons. in 1929 he was awarded the Nobel prize for physics. the idea came from einstein when he said that very short wavelength of light must behave like particles in some ways. this assumption gained acceptance when de Broglie came forward with his theory about the duality matter -
Period: to
Irene Joliot-Curie
Irene Joliot-Curie was a French chemist credited along with her husband for finding isotopes that are made artificially. They were join awarded the 1935 Nobel prize for the discovery. She is also the daughter of Nobel prize winner Marie Curie -
Period: to
Werner Heisenberg
he was born in germany in 1901 and in 1927 published his uncertainty principle which states that we can never know the exact position and velocity of a specific particle. -
Period: to
Linus Pauling
born in America Pauling was a theoretical physicist who is the only person to have won 2 unshared Nobel prizes. the first in 1945 for his work on the formation and structure of chemical bonds and his efforts to ban nuclear weapons testing -
Period: to
Rosalind Franklin
Rosalind Franklin was a British molecular biologist who is partially credited with discovering the shape of DNA. this is controversial because she was not originally given credit for her work due to friction between her and her colleague.