[CHEM 121] - Final Exam Guide - Comprehensive Notes for the exam (44 pages long!)
Document Summary
The study of matter and the changes it undergoes. Anything that has mass and takes up space. A pure substance composed of two or more elements chemically united in xed proportions. Must be used to break a compound into its elements. To isolate elements from its compound people used heat, electricity or light. Cannot be separate into simpler substances by chemical means. Element names have a variety of modern and ancient roots. Element symbols are derived from names but not common names. The periodic table is the most important learning and organizing concept in scienti c history. The number of elements that make up most of the relative abundance are very few. Mendeleev (1869) had information about around 21 elements. a. b. c. d. e. He gave some order to the elements by ordering them left to right from lightest to heaviest. He also knew about the unknown elements and knew their relative mass by organization.
