CHEM 1510 Lecture 1: Chemistry Chapter 2 Notes
Document Summary
Distinction between mixtures and compounds: a physical mixture can be separated, a compound (reacted chemically) cannot be separated by a physical means. The law of mass conservation: the total mass of substances does not change during a chemical reaction, reactant 1 + reactant 2 = product, total mass = total mass. Law of definite (or constant) composition: no matter the source, a particular compound is composed of the same elements in the same parts (fractions) by mass. Law of multiple proportions: if elements a and b react to form two compounds, the different masses of b that combine with a fixed mass of a can be expressed as a ration of small whole numbers. Cathode rays: ray consists of charged particles, ray consists of negative particles, these particles are found in all matter, discovery of electrons, robert millikan 1909, charge of electron is -1. 602 x 10^-19 c (coulombs)
