If we start off with no information and make a guess at something logical, then the development of that idea is mathematics, not science. Science is based upon observation first and after doing experiments, trends may be noticed and we can perhaps summarize the data into a Natural Law.Read More
n 1887 J.J. Thomson discovery of the electron was a significant step that led to a much deeper understanding of the microscopic properties of Nature. In this entry, I will discuss the famous Millikan Oil drop experiment which was done in 1909.
But recall that in his characterization of the properties of the electron he could only determine the charge to mass ratio, given by -1.76 times ten to the 11th Coulombs per kilogram. Was this ratio a result of two big values or two small values?
Robert Millikan was able to separate the ratio in order to show that the ratio was that of two small numbers and in this way he was able to extract the elementary charge and the electron mass. Comparing the electron mass to that of the lightest element, Hydrogen, it is found that the mass of an electron is 1800 times smaller. Indeed at that time this was the smallest particle known.Read More
Discussion of the discovery of the electron by J. J. Thomson in 1897 using a cathode ray tube. He was able to obtain the charge to mass ratio, but not the actual mass or charge. Later Millikan was able to separate the two. Indeed Thomson found a new state of matter which laid the foundations for quantum mechanics and a huge range of technologiesRead More
In this clip the Aufbau Principle of the electronic structure of the elements is shown as an example of the content of MCH multimedia’s General Chemistry tutorials. The Aufbau or building up principle makes use of the Hydrogen Orbitals and the Pauli Principle. Buy the General Chemistry Tutorial from MCH Multimedia: General Chemistry can be used alone or in conjunction with any introductory chemistry text book. In this module, all the topics found in AP (Advanced Programs in High School), and college level General Chemistry courses are covered. Learn in depth by working through the modules which are presented with clear verbal instructions and descriptions about chemical processes. There are many places where you can plot results and do...Read More