14-1 : Temperature and Thermal Energy

Temperature The measure of the average kinetic energy of the particles in a substance. The measure of the average kinetic energy of the particles in a substance. Temperature is NOT energy.

Temperature If particles move faster, they have more kinetic energy and the substance has a higher temperature. Temperature is the same no matter how much matter you have.

3 Common Scales for measuring temperature: - Fahrenheit Water freezes at 32 and boils at Celsius Water freezes at 0 and boils at Kelvin (subtract 273 from °C) Water freezes at 273 and boils at 373

Absolute Zero Experiments have led scientists to conclude that -273 °C ( 0 Kelvin) is the lowest temperature possible. Experiments have led scientists to conclude that -273 °C ( 0 Kelvin) is the lowest temperature possible. At this temperature, no more energy can be removed from matter. At this temperature, no more energy can be removed from matter.

There are three scales used to measure temperature. Kelvin Celsius Fahrenheit

Temperature is a measure of the average kinetic energy of the individual particles and Thermal Energy is the total energy of all the particles.

14-2 : The Nature of Heat

Heat Heat is the movement of thermal energy from one object to another. Heat is the movement of thermal energy from one object to another. Heat energy depends on the speed of the particles, the number of particles (the size or mass), and the type of particles in an object.

Heat Transfer Heat always flows from the warmer substance to the cooler substance. Heat always flows from the warmer substance to the cooler substance.

Heat Transfer-Radiation Radiation is the transfer of energy as electromagnetic waves – This energy causes the atmosphere’s molecules to move faster which causes an increase in temperature. – Examples: Fire The Sun

Heat Transfer-Conduction Conduction is the transfer of thermal energy from one material to another by direct contact. Example: –Touching something that is hot –Putting a metal object in a flame

Heat Transfer-Convection Convection is the transfer of thermal energy by the circulation or movement of a liquid or gas. – This circular motion is called a convection current Examples: –Boiling water –Wind

Conductors and Insulators Conductors conduct heat well. – Metals Insulators do not conduct heat well. – Wood, wool, straw, paper, cork, and some gases such as air.

Specific Heat The amount of energy required to raise the temperature of 1 kilogram of a substance by 1 Kelvin.

Energy Conversions