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427 BCE
Plato
Plato thought that atoms were triangles and atoms are made up of elements. -
400 BCE
Democritus
He theorized that all matter was formed of different types of tiny discrete particles. The properties of these particles determined the properties of the matter -
330 BCE
Solar system model
The solar system model created by plato was the first model to have the sun at the center of the solar system. This is important because the planets are spheres so it would make since for atoms to be spheres.The rotation of the planets around the sun is like electrons and others around the nucleus of an atom. -
522
The Alchemists
The Alchemists thought that all metals were formed by 2 principles mercury and sulfur -
Robert Boyle
Robert Boyle was the person who discovered that the volume of a gas decreases with a increasing pressure and vise versa -
Antone Lavoisier
He wrote the first extensive list of elements. -
John Dalton
John Dalton is best know for his pioneering theory of atomism, he also developed a way to calculate atomic weight and structures. He also formulated the law partial pressures. -
Billiard ball model
Its infers that atoms are spheres. This model was created by
John Dalton. -
Amedeo Avogadro
He hypothesized that equal volumes of gasses at the Sam- te-urgiré and pressure contain equal numbers of molecules. -
Dmitri Mendeleev
He was the one that put elements in order by weight and created the periodic table -
JJ Thompson
JJ Thompson discovered the existence of electrons. -
Pierre and Marie Curie
They proved the existence neutron’s- elementary particulates void of any electrical charge. -
Plum Pudding Model
The model accounted for 2 thing one is that electrons are negatively charged the second was that atoms have no net charge. This model was created my J.J. Thompson. -
Albert Einstein
Einstein mathematically proved the existence of atoms. -
Robert Millikan
While researching Robert Millikan found the charge that electrons give off. -
Ernest Rutherford
He discovered that atoms that make up a object have a nucleus. -
Neils Bohr
He proposed a theory of the hydrogen atom, based on quantum theory the same physical quantities only take up the same discrete values.electrons move around the nucleus but only in prescribed orbit the difference is put out as radiation. -
Henry G. J. Mosley
He thought to use atomic numbers to organize the periodic table insted of mass -
Electron cloud model
The electron cloud model shows us that we dont know exactly where an electron is at any given time, but the electrons are more likely to be in specific area. This model was created by Erwin Schrödinger -
Erwin Schrödinger
He created a wave equation that can calculate the energy level of a electron -
Werner Heisenberg
He formulated a type of quantum mechanics based on matrices to predict the location of electrons around the nucleus. -
James Chadwich
He proved the existence of neutrons- elementary particles David of any electrical charge.