2 What is Thermal Energy? Energy is the ability to do work It is required to move or change matter in any wayThermal energy is the total kinetic energy of particles that make up a substanceMore kinetic energy in particles means greater thermal energy
3 Check your Understanding Which object in the pictures below has the most thermal energy?
4 What is Kinetic Theory?Kinetic Theory describes the behavior of particles in relation to thermal energyThe three main points are…All matter is made up of atoms and/or molecules that act as tiny particlesThese particles are always in motion. Particles move faster at higher temperatures.At the same temperature, more-massive (heavier) particles will move slower than less massive (lighter) particles.
5 What is TEmperature?A measure of the average kinetic energy of the particles in an objectTells how hot or cold something isThermometers are used to find this valueUnits for temperature are degrees…CelsiusFahrenheitKelvin
6 Check your Understanding Which object in the pictures below has the greatest temperature?
7 How do thermometers work? Most substances expand when heatedThe liquid in the thermometers (usually colored alcohol or mercury) expand as the temperature increases1. Temperature rises2. Particles in thermometergain energy3. Faster particles cause them tomove farther apart and up thetube
8 What is TEmperature?A measure of the average kinetic energy of the particles in an objectTells how hot or cold something isThermometers are used to find this valueUnits for temperature are degrees…CelsiusFahrenheitKelvin
9 Temperature has 3 scales FahrenheitUsed in Unites StatesWater freezes at 32˚FWater boils at 212˚FCelsiusUsed by most other countries and scientistsOne ˚C is 1.8 (9/5) larger than one ˚FWater freezes at 0˚CWater boils at 100˚C
10 Temperature has 3 scales KelvinUsed to express very cold temperaturesOne Kelvin is equal to the size of one °C.Based on absolute zeroAbsolute zero is the temperature at which all molecular motion stops (0 K)
12 Check your Understanding A. What is the temperature of freezing water? 1) 0°F 2) 0°C 3) 0 K B. What is the temperature of boiling water? 1) 100°F 2) 32°F 3) 373 K C. What is the temperature of absolute zero? 1) 0°C 2) 32°F 3) 0 K
13 Temperature Conversions On the Fahrenheit scale, there are 180°F between the freezing and boiling points and on the Celsius scale, there are 100°C.180°F = 9°F = 1.8°F100°C °C °CIn the formula for the Fahrenheit temperature, adding 32 adjusts the zero point of water from 0°C to 32°F.TF = 9/5 TC orTF = (1.8 TC ) + 32
14 Temperature Conversions TC is obtained by rearranging the equation for TF.TF = TCSubtract 32 from both sides.TF = 1.8TC ( )TF = 1.8TCDivide by 1.8 =°F = TC(TF - 32) = TC1.8
15 Temperature Conversions The Kelvin temperature scalehas 100 units between the freezing and boiling points of water.100 K = 100°C or 1 K = 1°Cis obtained by adding 273 to the Celsius temperature.TK = TC