2 Thermal Energy and Matter Heat – transfer of thermal energy from one object to another because of temp. differenceHeat flows spontaneously from hot objects to cold objects
3 Thermal energy – total PE and KE of all the particles in an object Temperature – measure of how hot or cold an object is compared to a ref. pt.Related to avg. KE of the particles in an object due to their random motion through spaceThermal energy – total PE and KE of all the particles in an object
4 Thermal contraction – when the volume of a material decreases due to a decrease in temperature Thermal Expansion – increase in the volume of a material due to increase in temp.
5 Specific heat – amt. of heat needed to raise the temp Specific heat – amt. of heat needed to raise the temp. of 1g of a material by 1 degree Celsius
6 Heat and Thermodynamics Conduction – transfer of thermal energy with no overall transfer of matterOccurs within a material or between materials that are touchingOccurs slower in gases than in liquids or solidsThermal Conductor – material that conducts thermal energy wellThermal insulators – poor conductor of thermal energy
8 ConvectionConvection – transfer of thermal energy when particles of a fluid move from one place to another
9 Convection currents – occur when a fluid circulates in a loop as it alternately heats up and cools downImportant in many natural cycles such as ocean currents, weather systems, and movements of hot rock in Earth’s interior