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Joseph Proust
The law declared that the composition of a substance is always the same, no matter where it was found or how it was made. He studied different sources of many compounds. Contribuation :He found that they always contained the same ratio by weight of their elements. conclusion-the ratio by mass of the elements in a chemical compound is always the same -
John Dalton
He came up with his theory of atoms and was said to be accurate. the theory is called the Modern Atomic Theory, He came up with the idea that matter is made up of atoms which he believed that atoms who are identical cant be destroyed or rearranged.
conclusion- matter is made of atoms that are identical atoms that cannot be destroyed or rearranged in reaction
contribution-the modern atomic theory -
J.J. Thompson (charge/mass of the Electrons)
J.J. Thopmson found electrons by using the Cthrode Ray Tube by doing that he also noticed charge/mass of an Electron. He calculated it to be 1.759 x 108 Coulboms/gram.
Contribution: Helped get a better understand and view of the Atom
Conclusion: Electrons charge/mass is 1,.759 x 108 coulboms/grams -
J.J. Thompson (Leptons)
J.J. Thompson discoverd the Lepton and relaized it had relations with the Atom and its particles.
conclusion- discovered the leptons and its relationships with the atoms.
contribution-leptons -
Ernest Rutherford ( Postively charged Nucleus)
Ernest Rutherford discoverd the Nucleus by taking Gold Foil and using it to prove exisitence of a nucleus. By doing so he shot positivley charged particlues at the gold foil and noticed some went through the foil some deflected. He realized that the center of an atom is positive and that it contains empty space.
conclusion-the center of the atom is positive, atoms also contain empty spaces.
contribution-figured elctrons grouped around the nucleus -
Neils Bohr (energy levels)
Neils Bohr discoverd that electrons travel around the nucleus in paths. each path has a level. He came up with the idea that electrons even though travel in paths they can go past each other but can hop on one path to the next.
contribution: electron paths
conclusion: electrons travel in paths around the nucleus -
Ernest Rutherford ( charge/mass of the proton)
Rutherford discoverd the proton while undergoing an nitrogen gas experinment that involved some alpha particles. His resluts on the test should that the nitrogen atom broke down under great force from collision and the particle found was part of its nucleus
contribution: discoved the proton
conc;usion: used nitrogen gas and alpha particles to collide under great force and wat was left was part of a particle from the nucleus of the nitrogen atom. -
Ernest Rutherford ( Composition of Electricity)
Rutherford analyzied the( - +)elctrons that flow around the electrical current he used to anaylis its flow through the connector until an electiral aharge was present.
conclusion- analysised how the compositon works.contribution- composition of electricity -
James Chadwick (Neutrons)
James Chadwick discovered the neutron by performing radiation any by doing so he noticed that the particles had no electrical charge to them. So he called them Neutrons.
conclusion- particles had no electric charge, showig they were neutral particles.
contribution- concluded that particles of a beam from alpha particles hitting beryllium carried no electric charge they were neutral particles called neutrons -
Murray Gell Mann (Quarks)
He discoverd the existence of a new level of Atomic particles - quarks. These bits of matter when used kind act like building blocks of protons and neutrons. they helped explain some complex chemical substances.
contribution-helped to lay the base for our understanding of the components that make up matter
conclusion: discoverd the existence of a new level of atomic particles called Quarks