Unit 2 Test Review

Which BEST explains why metals are used instead of plastics to make frying pans?

• Plastics expand and limit tyhe heat transfer of heat energy

• Metals are conductors and transfer heat energy throughout the pans

• Metals contract and shrink as they transfer heat energy

• Plastics are insulators and allow the pans to expand as they absorb heat energy

Which material would make the BEST spoon for stirring something hot during the cooking process?

• wood

• Copper

• Aluminum

• Silver

On a hot day, heat can flow into a building through a glass window. On a cold day, heat can flow out of the building through the window. How does putting a curtain in front of the window slow down the change in temperature?

• The curtain keeps light from shining through the window and carrying heat

• Trapped heat between the curtain and window blocks the flow of air to the room

• The curtain keeps air from flowing through the window

• Trapped air between the curtain and the window is an insulator

Two metal containers full of ice, are on a table. Alicia wraps one container with layers of cloth. She does not wrap the other container.

What MOST LIKELY happens?

• Ice melts in the unwrapped container but not in the wrapped container

• Ice melts at the same time in both containers

• Ice melts faster in the unwrapped container

• Ice melts faster in the wrapped container

A boy holds his hand over a lighted electric bulb, not touching the bulb, and his hand feels the heat. Which kind of thermal energy transfer is this?

• Convection

• Insulation

• Conduction

• Radiation

Ehat can be concluded from the following statements about the properties of metal?

*A cast-iron skillet on a stove is used to fry bacon

*A metal spoon left in a pot of soup heating on a stove is too hot to touch

*An Aluminum playground slide gets hot on a summer day

• Metals conduct heat

• Metals are good insulators

• Metals combine with nonmetals

• Metals conduct electricity

In order for a material to be effective for cooking, it must have which physical property?

• Low thermal expansion

• High reactivity with water

• High electric charge

• Low melting point

Which physical property is important to have in a material used in cookware?

• High flexibility

• Good conductor of heat

• Poor conductor of heat

• Low flexibility

Which transfer of heat energy requires NO CONTACT between the heat source and the heated object?

• Conduction

• Convection

• Radiation

• Reflection

Some pans have copper along the bottom to help them heat evenly. How is the heat transferred from the stove to the copper of the pan?

• By absorption

• By radiation

• By conduction

• By convection