CHEM-UA 125 Chapter Notes - Chapter 2.2: Radium, Design Of Experiments, Robert Andrews Millikan
11 Aug 2016
School
Department
Course
Professor
Document Summary
Postulates of the atomic theory: all matter has atoms. How the theory explains the mass laws: mass conservation. Atoms can"t be created nor destroyed or converted into other types of atoms: definite composition. A compound is a combination of a specific ratio of different atoms, each with a specific mass: multiple proportions. Atoms of an element have the same mass and are indivisible. 2. 4 the observations that led to the nuclear atom model. Daltons model of the atom didn"t predict the existence of subatomic particles that led to the discovery of electrons and the atomic nucleus. Discovery of the electron and its properties. Matter and electric charge were related an electric current could decompose certain compounds into their elements: cathode rays. Scientists passed an electric current through nearly evacuated glass tubes fitted with metal electrodes. When the electric power source was turned on, a ray was seen striking the phosphorous coated end of the tube, emitting a light.
