Keeping Our Body Healthy Living things: Human life 162

4

Heat at Home

what heat is and how it is transferred about central heating and energy-efficient homes about temperature and how it is measured.

conduction, convection, kinetic energy, polystyrene, radiation Heat is a form of energy that transfers from something with a higher temperature to something with a lower temperature. Heat can be transferred in three ways: by conduction, by convection and by radiation.

Conduction

Energy is the movement of molecules. Matter is made up of molecules. When something is cold, its molecules move

Conduction occurs when heat moves from one object to another. An example of convection is when you touch a warm radiator in your home slowly because they have less energy. When something is heated, its molecules move faster because they have more with your hand. The heat from the energy. radiator moves to your skin, making it warmer. Another example is when you hold an ice cube in your hand. The heat from your skin moves to the ice, causing it to melt. A thermal conductor is a material that allows heat to easily pass through it. In other words, it lets the heat out. Metal and glass are good thermal conductors. A thermal insulator is a material that prevents heat from passing through it. In other words, it keeps the heat in. Wool and plastic are good thermal insulators.

Which materials are good conductors of heat?

Equipment: container of hand-hot water, metal spoon, wooden spoon, plastic spoon, butter

Action:

● Make a prediction about each spoon before you begin. ● Pour hand-hot water into a container. ● Place the handle of each spoon in the water. ● Put an equal-sized knob of butter on each spoon and watch as it melts. ● On which spoon does the butter melt first? What does this show? Which spoon is the worst conductor of heat?