CHY 104 Lecture Notes - Ernest Rutherford, Beta Particle, Electric Field
14 Jan 2013
School
Department
Course
Professor
Document Summary
The important postulates of dalton"s atomic theory are: all elements are composed of atoms. Atom is too small so that it could not be divided into further simpler components: atom cannot be destroyed or produced, atoms of an element are similar in all respects. They have same mass and properties: atoms of different elements combine in a definite simple ratio to produce compounds. It has two electrode, a source of electric current and a vacuum pump. (diagram) Sir william crooks (1895 performed experiments by passing electric current through gas in the discharge tube at very low pressure. He observed that at 10-4 (-4 is power to 10) atmosphere pressure, shining rays are emitted from cathode. Cathode rays are material particles as they have mass and momentum. Gold stein (1886) observed that in addition to the cathode rays, another type of rays were present in the discharge tube. These rays travel in a direction opposite to cathode rays.
