Heating and cooling Concept map of the topic Saturday 6 June 2009

Heating and cooling Heat is a form of energy – (kinetic energy of particles in the substance). Heat is measured in Joules Temperature is measure of level of heat – measured in o C. Heat flows from hot objects to cool objects. Conduction – in solids, liquids and gases as particles collide with each other. Best in metals, worst in insulators like wool. Convection – in liquids and gases only as hot, low density particles rise and cool high density particles sink. Radiation – by waves through air or a vacuum – best radiated and absorbed by dull dark surfaces. by Changes of state causes heating cooling Solids melt at their melting point – particles become free to slide past each other. Liquids boil at their boiling point – particles become free to move. Gases condense back into liquids. Liquids freeze into solids.