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Te mp er at ure (Sect. 8.2). There are two common temperature scales: Fahrenheit scale Water freezes at 32º and boils at 212º Celsius scale Water freezes at 0º and boils at 100º. F. C. Te mp er at ure (Sect. 8.2). What is Temperature?
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Temperature (Sect. 8.2) • There are two common temperature scales: • Fahrenheit scale • Water freezes at 32º and boils at 212º • Celsius scale • Water freezes at 0º and boils at 100º Jennifer C. Brown
F C Jennifer C. Brown
Temperature (Sect. 8.2) • What is Temperature? • Atoms are in constant motion, even in a solid object. • The back-and-forth jiggling of atoms is caused by thermal energy, which is a kind of kinetic energy. http://www.epa.gov/apti/bces/module1/kinetics/animation/kani1/kani104.htm Jennifer C. Brown
Temperature (Sect. 8.2) • Temperature measures the kinetic energy per molecule due to random motion. • Average motion leads to a speed. Random motion leads to a temp. Jennifer C. Brown
Temperature (Sect. 8.2) • A thermometeris an instrument that measures the exact temperature. • Most thermometers contain either a silvery fluid (mercury) or a red fluid, which is alcohol containing a small amount of red dye. • How do they work? Jennifer C. Brown
Temperature (Sect. 8.2) • Absolute Zero? = -273ºC = 0 K • Uses the Kelvin (K) Scale • You cannot have a temperature lower than absolute zero. • Think of absolute zero as the temperature at which atoms are “frozen.” To convert from Celsius scale to Kelvin scale, you just add 273 to your Celsius temperature. Jennifer C. Brown