Unit 3 Review

Identify each label to the corresponding area it identifies in the image.

(This means: match the term to the correct number.)

• 1

  Gas/Vapor

  2

  Temperature

  3

  Boiling

  4

  Liquid

  5

  Melting

  6

  Solid

  7

  Time

• • 1

    Time

  • 2

    Temperature

  • 3

    Boiling

  • 4

    Liquid

  • 5

    Ga/Vapor

  • 6

    Solid

  • 7

    Time

• • 1

    Gas/Vapor

  • 2

    Temperature

  • 3

    Liquid

  • 4

    Boiling

  • 5

    Melting

  • 6

    Solid

  • 7

    Time

Which particle has the most energy?

Responses

• ice (solid)

• water (liquid)

• steam (gas)

Heat is being removed (decrease in Kinetic Energy) from a substance at a constant rate starting in the liquid phase at 75°C and ending at 15°C. The graph shows the temperature change during cooling. What phase change is occurring?

• melting

• freezing

• boiling

• condensation

This curve indicates what about the heat energy?

• Heat energy is being added or absorbed

• Heat energy is being released

Predict the energy trend as a substance changes from a solid to liquid to gas on this graph.

• It would increase from bottom left to top right.

• It would decrease from top left to bottom right.

• It would increase from solid to liquid, then decrease from liquid to gas.

Predict the energy trend as a substance changes from a solid to liquid to gas on this graph.

• It would increase from bottom left to top right.

• It would decrease from top left to bottom right.

• It would increase from solid to liquid, then decrease from liquid to gas.

When a neon sign lights up, like the one you see here, something is happening to the neon atoms inside the tube. How is this colorful sign related to kinetic energy and phase change?

• The electrical current in the tube generates the neon gas that glows in the dark.

• Electrical energy excites the neon atoms. They spin faster in the tube producing electromagnetic waves that we see as colors.

• Electrical energy accelerates the electrons in the neon gas. The gas ionizes and becomes plasma, containing both positive and negative ions.

You placed a marshmallow in a syringe during a science lab. You pulled the plunger out increasing the volume in the syringe the marshmallow expanded. How can this best be explained?

BLT -Boyle's LAW

• As the pressure decreased in the syringe the volume of the marshmallow increased.

• As the pressure increased in the syringe the volume of the marshmallow increased.

• As the pressure decreased in the syringe the volume of the marshmallow decreased.

• As the pressure increased in the syringe the volume of the marshmallow decreased.

For the next experiment, several students placed a marshmallow Peep chick into the microwave. What is the BEST prediction of what will happen to the Peep chick once the microwave is turned on for 15 seconds?

(hint: molecular motion of solids, liquids, and gases-which one moves out the furthest?)

• The gas molecules inside the marshmallow chick heat up vibrate, increase the pressure outward and the chick expands.

• Whenever there is an increase in temperature there is an increase in volume so the chick expands.

• 
  Increased pressure due to increased temperature results in a decrease in volume so the marshmallow chick will begin to shrink.

You took a balloon outside on a very cold day. As you waiting outside the balloon began to shrink. What is the best explanation of this?

\Hint: What happens to energy (heat/kinetic) as temperature decreases. Why did the soda can in our lab shrink/crush?

• As the particles became cooler, they lost energy and moved less, resulting in less pressure on the balloon.

• As the particles became cooler, they lost energy and moved less, resulting in more pressure on the balloon.

• As the particles became cooler, they gained energy and moved less, resulting in more pressure on the balloon.

• As the particles became cooler, they gained energy and moved less, resulting in less pressure on the balloon.