Conduction is the transfer of thermal energy with no overall transfer of matter. For exzample, Newton's Cradle after one ball strikes the rest, most of the kinetic energy is transferred to one ball on the end. Conduction in gases is slower than in liquids and solids because the particles in a gas collide less often. Conduction is faster in metals because some electrons are free to move about.Convection is the transfer of thermal energy when particles of a fluid move from one place to another. For exzample passing sand bags along a line is transferring thermal energy by convection. Radiation is the transfer of energy by waves moving through space. For exzample heat lamps used in restaurents is an exzample. All objects radiate energy. As an objects temperature increases, the rate at which it radiates energy increases. A thermal conductor is something that conducts thermal energy well such as a copper pot or pan. A thermal insulator is something that conducts thermal energy very poorly such as using a wooden spoon in a hot pan to pick something up out of the pan. Temperatures are higher at the bottom of the oven because air at the bottom of the oven heats up, it expands and become less dense than the surrounding air. Due to the difference in density, the hot air rises. The rising air cools as it moves away from the heat source. As a result, the coolest air is at the top of the oven. The study of conversions between thermal energy and other forms of energy is called thermodynamics. The first law of thermodynamics states that energy is conserved. The second law of thermodynamics states that thermal energy can flow from colder objects to hotter objects only if work is done on the system. The third law of thermodynamics states that absolute zero cannot be reached.
( Newtons Cradle)