Phase Changes of Matter


Science is all around us!



Go to your freezer and pull out an ice cube. Go place the ice cube in a sunny spot outside. Observe what happens to the ice cube and ground for about 30 minutes. This is going to be what is called phase changes! What is the easy way to talk about that science term? You tell me!

Take a book or homework with you so you can multitask!


Read this article about the changing states of matter! As you read come up with an explanation of what the picture below means!

phase changes.jpg

Here is the article!


A change of state is when a substance physically changes from one form to another.


The particles in a solid are tightly packed together, and just vibrate in place. However, when you add energy, or heat, the particles begin to heat up and move around a little bit more. This changes the states from a solid to a liquid. Then, if you add even more energy, or heat, the particles in the liquid begin to move more and more. Then, the particles are moving so fast they change from a liquid to a gas.


phase change.jpg


Melting: Solid to liquid

When a solid reaches its melting point, energy is absorbed and the atoms or molecules begin moving more. The melting point is the temperature at which a substance changes from a solid to a liquid. For example, a piece of ice melting in the hot sun.




Freezing: Liquid to Solid

Freezing is the reverse process of melting. The particles lose energy, and they become closer to each other. The temperature at which liquid changes to a solid is called the freezing point. The freezing and melting points for each substance occur at the same temperature. For example when you put water in the freezer and it becomes a solid piece of ice.



Vaporization: Liquids to Gases

Vaporization includes evaporation and boiling. Boiling is vaporization that occurs through a liquid. When heat, or energy, is added the particles begin to move more and more. Once they reach the boiling point, the point at which liquid boils, the liquid then turns into a gas and begins to evaporate. Evaporation occurs at the surface of a liquid. For example, when there is a puddle on the ground and then after a few hours of the sun shining on it the puddle is gone. That is evaporation.


Puddle Evaporation.png


Condensation: Gases to Liquid

Condensation is the change from a gas to a liquid. For a gas to become a liquid the particles must lose energy and they become closer together. The particles slow down and become a liquid. For example, the water bubbles that appear on the outside of your glass left in a warm room.




Sublimation: Solid directly to a gas

A change of state directly from a solid to a gas is called sublimation. The particles in a solid are tightly packed and suddenly the attraction between the particles is overcome. An example of sublimation would be dry ice. Dry ice is a solid, and does not melt because it is so cold. It goes directly from being a solid to a gas.



During a change of state, the energy (you add or take away energy) of a substance changes. The identity of the substance does not!



In the web site below play the wild wild taxi game by pressing start on the first screen. Be sure to pay attention to the directions. As you go along in the race answer the questions. Play as many times as you need to so you can finish the race. You must at least beat the high score of 36,941. Take a screen shot of your score and submit it to the phase changes dropbox.




Students remember phase changes in many ways, but one of the most common is by using a graphic organizer. There is an example graphic organizer in the explain section and also one posted below. Take a look at it before you read on.




Create your own graphic organizer with all the phase changes on there. Also, show the particles in a solid, liquid, and gas, and what happens to all the particles as the phases change. Submit this to the phase changes dropbox. Be original and creative!



Can you answer today's driving question?

 What happens to particles when their temperature is increased or decreased?

Tasks to complete for today's lesson:






 Read the article and determine what the picture means.


 Crazy Taxi Game Score Submission

 Graphic Organizer