Is the total energy of motion in the molecules of a substance. Gases are made of molecules that are constantly moving. The faster they are moving the more energy they have. Fast More Energy Slow Less Energy Thermal Energy
The average amount of energy of motion in the molecules of a substance. It is a measure of how hot or cold something is. Temperature More Energy Warmer Less Energy Cooler
Thermometer- An instrument used to measure the temperature, consisting of a thin, glass tube with a bulb on one end that contains a liquid, usually mercury or alcohol. – Liquids expand when heated or contract when cooled. – It is measured in degrees Celsius or Fahrenheit. Freezing 0°C = 32°F Boiling 100°C = 212°F Measuring Temperature
Speed of Molecules & Temp What happens to the speed of the molecules when temperature is increased? What happens to the amount of times the walls are hit?
Temperature and Volume What happens to the volume of a gas when it is heated?
Heating air molecules increases their energy making them move faster. As a result, they will hit the wall more often, moving the wall to the right. –Lowers the pressure on the warmer side –Increases pressure on the cooler side. Air Molecule Model Situation 3 Faster Molecules Slower Molecules
Cooling air molecules decreases their energy making them move slower. As a result, they will hit the wall less often, moving the wall back to the left. –Pressure on the right side is higher, pushes back towards the left side which has a lower pressure. Air Molecule Model Situation 4 Faster Molecules Slower Molecules
The energy transferred from a hotter object to a cooler one. Three ways it is transferred. –Radiation –Conduction –Convection Heat
The direct transfer of energy over long distances of empty space. Moves in waves. (Electromagnetic Waves) No direct contact Can not see it, but feel it a heat (Infrared) –Sunlight –Open fire Climate Radiation
Heat transfer by direct contact of particles of matter. (Transfer by Touching) Particles bump into each other and transfer their energy heating them up. –Putting your hand on a hot stove. Conduction
Heat transfer by the circular movement of a fluid (liquids and gasses). Particles flow transferring heat energy. Caused by differences in density. Convection
Density: the amount of mass in a given volume. D=M/V Heated Fluids: –Move faster and bump into other particles. –They spread out increasing the volume. –Density decreases Cooling Fluids –Move slower –They come together decreasing the volume. –Density increases How Convection Works
Heat Transfer in the Troposphere Radiation, conduction and convection work together to heat the troposphere. The surface absorbs solar energy. Air near the surface is warmed by radiation and conduction of heat from the surface to the air.
Heat Transfer in the Troposphere Convection causes most of the heating of the troposphere. Convection Current- –Heated molecules have more energy. –They move faster and spread further apart. –Air becomes less dense and rises. –Cooler air is more dense and sinks. –Moves into the place of the rising air.