-
2000 BCE
The Alchemists
It first started as Egyptians and Babylonians. They believed that all metals were formed from two principles, mercury and sulfur. Also to manipulate the properties of matter in order to prepare more valuable substances. -
460 BCE
Democritus
Democritus was an ancient greek pre-socratic philosopher. He was one of the two founders of the ancient atomist theory. The discovery of atoms. -
428 BCE
Plato
The atomic number theory in which ideal geometric dorms serve as atoms. In other words aa suit of programs for electronic structure calculation. -
4 BCE
Aristotle
The proper mixing could occur when substance of comparable amount are brought together to yield other substances called, compounds. -
Lavoisier
Antoine-Lauernt de Lavosiser discovered the role of oxygen in combustion and reparation, proved law of conservation reformed the chemical nominal nomenclature and named hydrogen. Hew as born August 26,1743 and died May 8. 1794. -
John Dalton
John Dalton was an English/British chemist, physicist, and meteorologist. He is known was the father of chem. He comprised all matter of indivisible and indestructible with distinct masses and properties He was born September 6, 1766 and died July 27, 1844. -
Newlands Law of Octaves
It was made by an English chemist, J.A.R. Newlands. It's when elements are put together in increasing atomic mass order the properties of the eight elements are the same as the first. Only for the elements up to calcium because some elements do not match chemical properties. -
Mendeleev's Pd. Table
Dmitri Mendeleev put in order of increasing weight and broken into rows such that elements in each column shared valence. ( The number of another atomic number +other properties) -
Photoelectric Effect
Heinrich Rudolf Hertz discovered electrically charged particles are released from/within a material when it absorbs electromangnetic radiation. When election af electrons from a metal plate whne light falls on it. -
Discovery of Radioactivity
Herri Becquerei found radioactivity when he was looking over Rontagen's early x-ray images. Elemnts, polonium and radium occur naturally in uranium minerals. Medicine was made for it. -
Discovery of the Electron
It was found first by J.J Thomson. Scientists looked for cathode rays for the carrier of the electrical properties. They then found this. Opened the most rapid advance in physical science leading up to views of the atomic structure and Chem. -
Planck's Quantum Theory of Light
Max Planck's theory was that light bulb filaments should be heated to a temperature of about 3,200 kelvin to ensure the most of the energy is emitted as visible waves. -
Plum Pudding Model
It was first shown by J.J. Thomson. It was defined by electrons surrounded by a volume of positive charge like negative charged "plums" embedded in a positive charged "pudding". -
Rutherford's Gold Foil Experiment
A piece of gold foil was hit with alpha particles. Most of them went right trough. Gold atoms were mostly empty spaces. -
Bohr's Planetary Model
It was made to explain how electrons can have stable orbits around the nucleus. The electron was able to occupy only certain orbits around the nucleus. -
Moseley's Atomic Number
Henry Moseley found the atomic number of positive charge in the atomic number. Atomic numbers 436,175 between aluminum and gold are unknown. -
Discovery of Proton
Ernest Rutherford proved that the nucleus of the hydrogen atom is present in the nuclei of all other atoms. His research resulted in a nuclear reaction that led to the first splitting of the atom -
Charge of the Electron
Electron, lightest stable subatomic particles known. It carries a negative charge of 1602176634x10(-19) Coulomb. (basic unit) -
Schrodingers Equation
A linear partial differential equation that governs the wave fountain of a quantum mechanical system. -
Heisenberg Uncertainty Principle
Werner Heisenberg states we can not know both position and speed of a particle (like photon or electron) with perfect accuracy. The more we nail done the particles position the less we know about the speed. -
Discovery of the Neutron
James Chadwick was convinced that alpha p. didn't have enough energy to produce powerful gramma-rays. Core also contained a new uncharged particle. -
Roberts Millikan
Robert Andrews Millikan's atomic theory was the elementary charge of an electron using the oil-drop experiment. He was born March 22,1868, and died December 19, 1953.