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Antonie Lavosier
Discovered that matter cannot be created or destroyed in a chemical reaction. This law is known today as "The Law of Conservation of Mass". -
Period: to
Atomic History
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Joseph Proust
Proust discovered the "Law of Defininte Proportions", which states that the number of elements in a compound is always the same. He also believed that atoms were like "legos" because he believed that they could be put together in a certain way to make something bigger. -
John Dalton
Dalton's atomic theory said that elements made of tiny particles were called atoms. All atoms of an element were identical. Dalton's theory also said that chemical reactions involce the rearrangement of combinations of atoms. -
William Crookes
Discovered cathode Rays could travel in straight lines from the cathode; causes glass to fuoresce; impact a negative change to ojects they strike; which are defelected by electric fields and magnets to suggest a negative charge; cases pinwheels in their path to spin indictating that they have mass. -
Marie Curie
Marie's atomic theory proved that the atoms of one element were indivisible. Henri Becquerel's uranium rays in 1896; one of the givens of physical science was the atom was indivisible and unchangeable. -
Max Planck
Max's discovery of the atomic theory he had two rules to follow. Planck then combined the two laws and made a special hypothesis, (the quantum hypothesis). The theory gave details about why vibrating particles of light could emit forms of energies. -
Albert Eintstein
Einstein applied the quantom theory to light to explain the photoelectric effect, by which a material will emit electrically charged particles when hit by light. Also found experimental proof of the existence of atoms, in which tiny particles were suspended in water. -
Ernie Rutherford
He discovered that the atom is made up mostly of empy space. Rutherford also discovered that the atom was made not only of protons, but of neutral charged neutrons. Lastly, he discovered that the electrons fly around the nucleus occupying the empy space. -
Neils Bohr
Rutherford student. He proposed a model for the hydrogen atom that was consistant wth Rutherford's model. According to Bohr, hydrogen atoms absorb light when an electron is excited from a low energy orbit. -
J.J Thompson
Thompson discovered the electron, and the proton. He discovered that the electron is negatively charged and the proton is positively charged. He also discovered that the atom can be divided. -
Werner Heiesenberg
had a theory of his own called matrix mechanics which also explained the behavior of atoms. Heisenberg based his theory on mathematical quantities called matrices that fit with the conception of electrons as particles. -
Friedrich Hund
Famous for his contributions on the Quantom theory. His main help to the theory wasconvering the structure of the atom. Also, about the molecular spectra. -
Louis de Broglie
Broglie's ideas for the atomic theory were a basis of developing the wave mechanics theory. This theory has helped improve our knowledge on the physical nature on the atomic scale. -
Erwin Schrodinger
Took the Bohr model one step furher. He used mathematical equations to describe the likelihood of finding an electron in a certain position. -
James Chadwick
Discovered the particles in the nucleus of an atom that became known as the neutron because it has no electric charge. -
Glenn Seaborg
Synthesized 6 transuranium elements and suggest a change in the layout of the periodic table.