Conductors and Insulators Chapter 8 Lesson 3

What are conductors & insulators? CONDUCTORS- are material that easily conducts heat energy They heat up quickly and evenly when exposed to a source of thermal energy: gold, copper, silver INSULATORS- materials that do not heat well Insulators absorb heat and do not distribute evenly Gases, many nonmetals, wood, plastic, and glass The better the insulator, the slower heat energy will move through the material Some physical properties, such as boiling point and freezing point, require testing or investigations Thermal Conductivity is the ability of a material to transfer heat

Examples Answer= D Insulators do not allow heat to move through easily.

Examples Answer= B Conductors allow heat to pass through easily

How are conductors and insulators used? You use them every day. Thermal conductivity can be a very useful property and many things in the kitchen are made of metals Frying pans need to be made out of conductive material so that your food will cook evenly. Engineers, builders, and architects make decisions on which materials are used Insulation is a material that is used to prevent heat from flowing into or out of a building. It keeps buildings warm in the winter and cool in the summer Cloth, plastic, fiberglass, air, and other insulators can be used as insulation Most houses and buildings have some type of insulation

How are conductors and insulators used? Your clothing is also made of insulators Bulky winter coats, sweaters, fleece jackets have material that trap hair Wearing multiple layers of clothing has the same effect Between each layer of clothing is a layer of air that is warmed by your body’s heat Many insulators can be found in nature Birds have a layer of soft, fluffy feathers called down. The down feathers trap air and keep it close to the bird’s bodies, helping them maintain their body temperature The hair and fur found on many mammals works the same way. Ocean mammals, such as whales and dolphins, have a layer of fat called blubber

How conductors/insulators are used examples Answer=A Remember that most of our clothing are insulators because we want to trap the air around us to keep us warm. Wearing a knitted hat will keep you warm, especially in colder weather

More examples Answer= C Rubber is an insulator because it does not allow heat to pass through. If it did, you would burn your hands every time you touched the handle. The pot needs to be a conductor in order for you to cook your food. Most metals are good conductors and copper is a metal!

Do conductors have other uses? Conductivity can also be used to describe the ability of a material to conduct electricity Materials that are good thermal conductors, such as metals, are often good electrical conductors as well. Metals are good electrical conductors: copper is often used in electrical wires. Rubber and plastic are insulators because they do not allow electrical charge to flow. They are usually placed around metal wires to protect you from electrical shock Water is an electrical conductor. Never touch a power cord, switch, or electrical appliance while you are wet or in water

Conductors other uses examples Answer= B Metals are not only good conductors of heat, but also electricity

Conductors other uses examples Answer= D Isabella is the only student who has ALL metals in her pile of materials. Metals are good conductors of heat and electricity

How conductors/insulators are used examples Answer= C Many metals are good conductors. When heated, these can easily transfer heat.