Science CBA #6

Snow turns to liquid water when it​ (a)  

• melts
• freezes
• condenses
• evaporates

Electrical wires are coated with a rubber or plastic because these materials are good

• resistors.

• magnets.

• insulators.

• conductors.

The magnetic force between opposing poles of two magnets is​ ​ (a)  

• an attractive force
• a repelling force

Turning off the light when leaving a room is an example of

• conserving energy.

• wasting energy

• using potential energy

• using chemical energy

Zoe is investigating the forces between bar magnets. She draws the diagram shown here.

This diagram shows bar magnets. She wants to add an arrow between the magnets to show the magnetic force. What is the best choice?

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An electric bulb will stop shining when a light switch is shut off because the switch​ ​ (a)  

• creates a gap in the circuit.
• draws electrons away from the light
• inserts a semiconductor
• reverses the direction of the current

Which material best conducts heat and electricity?

• metal

• plastic

• rubber

• wood

A science class is learning about different energy sources. Which example comes from a renewable source of energy?

• .

  water heated by solar panels

• food cooked over natural gas

• electricity produced from coal

• an engine powered by gasoline

Objects made of ​ (a)   can generally be used as conductors of electrical current.

• metal
• rubber
• plastic
• wood

Wood is considered a renewable resource because​ ​ (a)  

• trees can be replanted
• oxygen is released by trees
• there are many varieties of trees
• trees are used for many purposes