1.1: Chemistry - The Central Science Chemistry is the study of matter and how it behaves. The scientific method is the general process by which we learn about the natural universe. 1.2: Physical Quantities - Units and Scientific Notation To understand chemistry, we need a clear understanding of the units chemists work with and the rules they follow for expressing numbers. 1.3: Measuring Mass, Length, and Volume The SI base units specifies certain units for various types of quantities, based on seven fundamental units. We will use most of the fundamental units in chemistry. This section addresses the measurements: mass, length, and volume 1.4: Measurement and Significant Figures Significant figures properly report the number of measured and estimated digits in a measurement. There are rules for applying significant figures in calculations. 1.5: Rounding Off Numbers Before dealing with the specifics of the rules for determining the significant figures in a calculated result, we need to be able to round numbers correctly. 1.6: Problem Solving - Unit Conversions and Estimating Answers A unit can be converted to another unit of the same type with a conversion factor. Using this method, called dimensional analysis or the factor label method, is an essential skill that will be applied in many chapters of this textbook. 1.7: Density and Specific Gravity Knowledge of density is important in the characterization and separation of materials. Information about density allows us to make predictions about the behavior of matter.