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Aristotle
Aristotle believed in an infinently divisible particle. He was a student of plato and taught alexander the great.Aristotle was the first to believe in the existence of elements. He believed all things were made up of or a combo of air, fire, water, earth, and aether. aether was the divine particle that made up stars and planets. These ideas were very strange compared to beliefs of this time. -
400
Democritus
Was the first to believe that all matter was made up of atoms. He was the teacher of plato who taught Aristotle. The idea of his that all matter was made up od particles he called atoms was revolutionary. Before this time there had been no theories that suggested all matter was made up of a combination of base components. He began research into atomic structure. He formulated a set of beiefs that stated that all atoms are in constant motion, will remain that way forever, and have always moved. -
Antoine Lavoisier
Lavoisier was the thinker behind the law of conservation of mass.
He was the first in 2000 years who felt that there should be another look at atomic theory. Aristotle taught alexander the great who became a military leader and was very oriented around the aristotle mindset so he imposed aristotles beliefs. Lavoisier discovered the chemical properties of oxygen. He reaserched some basic chemical reactions and disproved old theories. He showed combustion, burning, and corrosion. -
John Dalton
John Dalton was revolutionary in defining a still commonly accepted set of rules for chemical reactions. With slight alterations and accounts for new discoveries(atomic fission for example)the rules he laid forth are still very much accepted today. He also set forth rules dealing with atomic properties and relations during chemical reactions. He also defined an atom as a solid, indivisible sphere. He also stated compounds have consistent properties and material input. -
Henri Becquerel
He is credited with being the first in his team(included the curies and others)to have discovered radioactivity. he placed uranium salts on phosphoric paper and put them in a pitch black drwer but a light imprint was made within 2 days by the uranium salts. He then experimented further with radioactivity and won a nobel prize in 1903 in conjunction with the curies. -
JJ Thomson
JJ thomson was not only the teacher of the legendary ernest rutherford he also discovered the electron. He also the plum pudding model which proposed that negative particles(electrons)were embedded in a large sphere of positively charged matter.The electron was the first of the the main subatomic particles discovered. -
Max Planck
Max planck was credited with discovering that energy is radiated in minute and discrete packages(which he later named quanta). Albert einstein planck's research for his theories. Planck also had his own quantum theory. Planck also created a theroretical model that was a precursor to bohr's. -
Robert Millikan
Robert millikan accuratley dtermined the charge of electron. He also proved that charge was equal across all electrons. He also used ionization chambers to advance study in cosmic radiation. -
Ernest Rutherford
Ernest Rutherford is one of the most significant atomic theory scientists there ever was. His biggest acomplishment was the discovery of the nucleus. He found that there was a center that contained most of the poitive charge and mass. He found alpha and beta rays in uranium radiation. He worked with niels bohr in 1912 and henry moseley in 1913 and frank soddy. He also proposed disentigration theory. He was taught by JJ thomson and taught/inspired james chadwick. -
Niels Bohr
Bohr worked for JJ thomson and was Ernest Rutherford's student. He won a nobel prize for his research. He is mainly famous for bohr diagrams that showed how electrons orbit the nucleas. While his model has been replace with a new one he still had the best modle for a long time. He also showed how atoms could determine the bonding capabilities of atoms. -
Marie and Pierre Curie
The team discovered polonium and radium. Their main project though was using radiation for X rays.After Pierre was killed by a streetcar marie vowed to finish their research. They won a nobel prize along Henri Becquerel. The couple greatlhy advanced radiation and in WW1 marie used X rays to help treat french soldiers. -
Henrey Moseley
Proved the theory by bohr that the frequency of the radiation depended on atomic charge, specifically in X rays.Unfortunantly his career was only 40 months long as he was killed during his service with the british army. He worked closely with bohr and primarily researched radioactivity. -
Erwin Schrodinger
Schrodinger created the quantum mechanical model which is the most recently updated model. This model shows the likelyhood of and electron in a certain position of its orbit. The more shaded area show a higher likleyhood of the electron being in that orbit. This is the most accurate model to date. -
Werner Heisenberg
Heisenberg stated his famous principle of uncertainty, which lays it down that the determination of the position and momentum of a mobile particle necessarily contains errors the product of which cannot be less than the quantum constant h and that, although these errors are negligible on the human scale, they cannot be ignored in studies of the atom. Heisenberg also worked with bohr. -
James Chadwick
James Chadwick discovered the neutron. This was one of the hardest particles to find as it emits no charge and was invisible to most detection that was used then. The neutron was ideal for bombarding uranium as it had no charge. Initially chadwick believed the neutron to ba a proton electron bond.
