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Democritus thought that atoms were uniform, solid, hard, incompressible, and indestructible and that they moved in infinite numbers through empty space until stopped. -
Everything in motion is always moved by something else. -
Plato's theory is that the physical world is not as real or true as timeless, absolute, unchangeable ideas.
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The Alchemists was a group of scientists in the 16th century. Some of the scientists were Robert Boyle, Lawrence M. Principe, and Paracelsus. -
Lavoisier atomic theory is that matter is not destroyed nor created in chemical reactions.
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The first part of John Dalton's atomic theory is that matter is made up of atoms which are invisible. The second part is that all atoms of a given element are the same size and have the same properties. The third part is that compounds are combinations of two or more atoms.
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Newland's law of octaves was founded in 1864 and stated that if the chemical elements are arranged according to increasing atomic weight, those with similar physical and chemical properties occur after each interval of seven elements. -
Robert's first major find was accurate determination of the charge carried by an electron using the elegant falling-drop method.
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Mendeleev made his periodic table in 1869, he arranged it so the groups with similar properties fell into a vertical table. -
Wilhelm Roentgen exposed potassium muranyl sulfate to sunlight and then placed it on photographic plates wrapped in black paper, assuming that the uranium absorbs the sun's energy and then emits it as X-rays. -
In the 1880s and the 90s scientist searched cathode rays for carries of the electrical properties then it was discovered by J.J Thomas in 1897. -
The Plum pudding model is on of the older models for the atom. -
This theory is when particles can emit or absorb energy in quantities only. -
In his experiment gold foil was hit by alpha particles with a positive charge most of them went through but this shows that gold atoms are mostly empty space. -
Robert Milikan discovered the charge of an electron by using negativity charged oil droplets, the charge of an electron is 1.60217663 × 10-19 coulombs. -
In Bohr's model the electrons travel around the nucleus of the atom in distinct circular orbits. -
Mosely published a paper where he concluded that the atomic number is the positive charges in the nucleus. -
This equation is a linear partial differential equation that governs the wave function of a quantum-mechanical system. -
James Chadwick announced in May 1932 that the core also contained a new uncharged particle, which he called the neutron. -
This principle states we can not know the exact position or speed of a particle like a proton or electron. -
James Chadwick in May 1932 announced the core also had a new uncharged particle the neutron. -
The photoelectric effect is where a electrical charged particle is released from a material with it absorbs electromagnetic radiation.