Temperature Heat and Thermal Energy Thermal Energy The

Temperature, Heat, and Thermal Energy

Thermal Energy The measure of the TOTAL amount of energy in ALL of the particles in an object or substance. n Objects with the same Temperature do NOT necessarily have the same total energy. n Ex: 2 L of Water @ 75 C > 1 L @ 75 C n

Temperature n Measure of the average kinetic energy in the particles of a substance – a measure of how fast the particles are moving around in the substance

Temperature Scales n Fahrenheit (F) - Commonly used in the United States. 32°F is assigned as the temp. water FREEZES while 212°F is assigned as the temp. water BOILS. n Celsius (C. ) - Commonly used in most of the World (as well as in science). 0°C is assigned as the temp. water FREEZES while 100°C is assigned as the temp. water BOILS.

Kelvin (K)- Commonly used in Physical Science. 273 K is assigned as the temp. water FREEZES while 373 K is assigned as the temp. water BOILS. Absolute Zero (0 K) means no movement of particles n CONVERSIONS: n Fahrenheit to Celsius: n • 5/9 x (F-32) = C n Celsius to Fahrenheit: • 9/5 C + 32 = F n Celsius to Kelvin: • C + 273 = K

Heat n The movement of Thermal Energy from a substance with Higher temp. to another with Lower Temp. n 3 types of Movement: n -Conduction n -Convection n -Radiation

Conduction n Heat is transferred by contact between particles without the movement of the particles themselves. n Ex: A spoon in boiling water n An Oven Coil and a metal pot

Convection Heat is transferred by the movement of CURRENTS within a fluid (liquid or gas) n Convection Current – The flow of heat through a fluid. Warmer less dense fluid rises while cooler more dense fluid falls, creating a flow/current n

Radiation Heat is transferred through Electromagnetic waves n Ex: Warmth from a Bonfire or Heat Lamp n Does not require matter to transfer (can transfer heat through “outer space”) n Ex: Sun’s radiation travels through empty space to reach Earth n

“Heat Moves one Way” n Heat flows from WARMER objects to COOLER objects until both have SAME temp.

Which direction will heat flow? n Your pillow and your head – Head Pillow n Your seat and your body – Body Seat n Hot food and the room – Food Room

Conductors n Conductor – Any material in which thermal energy is transferred quickly – Particles tend to be close together n Examples: – Common metals: § Copper § Iron (skillet) – Diamonds

Insulators n Insulator – Any material in which thermal energy is transferred slowly – Particles tend to be farther apart n Examples: – – – Cotton Cardboard Wood Rubber Plastic