A. Introduction to Chemistry, Atoms and Elements（答介绍化学、原子和元素）.pdf

Atoms A. Introduction to Chemistry, Atoms and Elements Importance of Chemistry Question: If cataclysmic event were to destroy all knowledge of science what would be the most important knowledge to pass on to future generations? Answer: Everything is made of Atoms. Atomic Theory is the central theme of chemistry and most important idea in science. Chemistry is central to science Chemistry deals with matter (STUFF of the world) and transformations of matter It is important and essential in physics, biology, geology, dentistry, medicine, nursing, engineering, philosophy, ….etc. Chemistry is NOT just beakers and test tubes in labs Chemical processes are going on everywhere all around us and inside us All the stuff you see around you is made of atoms and you are also made of atoms. Examples: Breathing O binds to Fe in Hemoglobin in red blood cells and thousands of other 2 chemical processes going on in our cells and bodies We get energy from food we eat sugar + oxygen  carbon dioxide + water + energy We get energy for industry by combustion butane + oxygen  carbon dioxide + water +energy Chemical reaction is: (a balanced chemical equation is shown below) Reactants  Products butane + oxygen  carbon dioxide + water + energy 2C H + 13O  8CO + 10H O + energy 4 10 2 2 2 1 History of Chemistry Five Historical Periods related to development of Chemistry 1) Practical Arts – 600 B.C. (ancient to present in some places) Chemical Processes were based on experiences No theoretical basis or understanding of chemical principles but they knew how to do many chemical processes such as: Preparation of dyes and medicines Manufac