CHEM 1411 Lecture Notes - Lecture 1: Scanning Tunneling Microscope, Kelvin, Si Derived Unit
Document Summary
All matter is composed of atoms and molecules. Chemistry is the science that investigates the properties of matter by examining the atoms and molecules that compose it. Science begins with the observation of the physical world. A number of related observations can often be summarized in a statement or generalization called a scientific law. A hypothesis is a tentative interpretation or explanation of observations. One or more well-established hypotheses may prompt the development of a scientific theory, a model for nature that explains the underlying reasons for observations and laws. Laws, hypotheses, and theories all give rise to predictions that can be tested by experiments, carefully controlled procedures designed to produce critical new observations. If scientists cannot confirm the predictions, they must modify or replace the law, hypothesis, or theory. We classify matter according to its state (solid, liquid, or gas) or according to its composition (pure substance or mixture).
