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460
Democritus Theory
He asked: Could matter be divided into smaller and smaller pieces forever, or was there a limit to the number of times a piece of matter culd be divided. Democritus called atoms "atomos". 460-370 BC -
Dalton Theory
Theory to Dalton: all matter made of atoms indivisible and indestructible.
*all atoms of a given element are identical in mass and properties.
*compounds are formed by a combination of two or more different kinds of atoms.
*a chemical reactio is a rearrangemnt of atoms.
TESTED BY THE BILLARD BALL -
Thomson Theory
thomson thory suggested that the atom is not indivisible and was apart of smaller pieces-- electrons and protons.
*atoms consist of a spear of positive charge with negative charge embed. THE PLUM PUDDING -
MAX PLANCK theory
Devised a theory that perfectly described the experimental evidence but a new idea apperared. The theory was that energy did not flow in a steady continuum, but it was delivered in discrete packets Planck later called quanta. A quantum is the minimum amount of any physical entity involved in an interaction. (http://www.pbs.org/wgbh/aso/databank/entries/bpplan.html) -
Rutherford Theory
Rutherford thought the atom must have almost all of its mass concentrated at its center, in a nucleus, with the vast majority of the atom conssting chiefly of empty space. MODEL/ GOLD FOIL EXPERIMENT -
Bohr Theory
REFINED RUTHFORD'S MODEL in 1913 proposing that electrons orbit the nucleus without losing energy and could only move in fixed orbits of specific energies. MODEL: QUANTUM MODEL OF THE ATOM -
Louis de Broglie Theory
Louis suggested the light electrons could act as both particles and waves. His hypothesis confirmed in experiments showed electron beams could be defracted or bent as passed through a slit as light could do. TESTED THE BOHR MODEL -
Werner Heisenberg
Theory: you must shine a wave legth of light on it that's smaller than the electron light. MODEL WAS QUANTUM MECHANICS -
Erwin Schrodinger Theory
Erwin derived a set of equations or wave functions in 1926 for electrons. According to him, electrons confindedin their orbits would set up standing waves, and you could describe only the probibility of where the electron could be. TOOK, AND TESTED IDEAS DEVELOPED BY DE BROGLIE -
Chadwick Theory
This theory identified the neutron, found out the particle proposed about Rutherford as significant mass and no charge. COLLABORATOR OF RUTHERFORD -
MAX PLANCK resigned
in 1937, Max Planck resigned his post as President of the Kaiser Wihelm Institute in protest of the Nazi's actions against Jewish scientists. http://www.pbs.org/wgbh/aso/databank/entries/bpplan.html
