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Democritus
All things are made of indestructible, indivisible atoms that are always moving and never stop moving. Two types of reality, atoms and voids (blank, empty space). atomos = indivisible -
Dalton
Every element is made of different atoms with different masses. Compounds are numerous atoms or elements combined. His model looked like a marble. He also established the atomic theory. -
Eugene Goldstein
Aided Thomson in many of his discoveries. He also found that ions have charges (+/-). Worked with cathode rays and worked on the basis of mass spectrometry. -
J.J Thomson
By experimenting with the cathode ray, he found when magnets deflected the rays there were smaller particles, called electrons. Plum pudding model of the atom. -
Marie Curie
She discovered the element of radium, and altered the way scientists think about energy and matter. -
Robert Millkin
By using the "Oil Drop" experiment he found how to get an electrons mass with the help of Thomson. Also attempted to measure the effect of individual subatomic particles. -
Ernest Rutherford
He discovered the noble gas thoron and also discovered the concept of the nucleus. -
Niels Bohr
He applied the quantum theory to Rutherford's atomic structure by assuming that electrons travel in stationary orbits, leading to the calculation of energy levels. -
James Chadwick
He discovered the neutron, which aided in the creation of Uranium-235 that led to the creation of the atomic bomb.