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Some Important SI Units in Chemistry

Let s discuss some of the SI units for quantities that we use early in the text length, volume, mass, density, temperature, and time. (Units for other quantities are presented in later chapters, as they are used.) Table 1.3 shows some useful SI quantities for length, volume, and mass, along with their equivalents in the English system. [Pg.14]

Length The SI base unit of length is the meter (m). The standard meter is defined as the distance light travels in a vacuum in 1/299,792,458 second. Biological cells are often measured in micrometers (1 j,m = 10 m). On the atomic-size scale, nanometers and picometers are used (1 nm = 10 m 1 pm = 10 m). Many proteins have diameters of around 2 nm atomic diameters are around 200 pm (0.2 nm). An older unit still in use is the angstrom (1 A = 10 m = 0.1 nm = 100 pm). [Pg.15]

Volume Any sample of matter has a certain volume (V), the amount of space that the sample occupies. The SI unit of volume is the cubic meter (m ). In chemistry, the most important volume units are non-SI units, the liter (L) and the milliliter (mL) (note the uppercase L). A liter is slightly larger than a quart (qt) (1 L = 1.057 qt 1 qt = 946.4 mL). Physicians and other medical practitioners measure body fluids in cubic decimeters (dm ), which is equivalent to liters  [Pg.15]

As the prefix milli- indicates, 1 mL is 7 of a liter, and it is equal to exactly 1 cubic centimeter (cm )  [Pg.15]

Problem The volume of an irregularly shaped solid can be determined from the volume of water it displaces. A graduated cylinder contains 19.9 mL of water. When a small piece of galena, an ore of lead, is added, it sinks and the volume increases to 24.5 mL. What is the volume of the piece of galena in cm and in L  [Pg.16]


General Features of SI Units 14 Some Important SI Units in Chemistry 14 Extensive and Intensive Properties 20... [Pg.895]


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