Activities

1. Match the process to the phases of matter.  
   
   

   s → g

   l → g

   g → s

   s → l

   l → s

   g → l

1. Evaporation
2. Condensation
3. Freezing
4. Melting
5. Sublimation

2. Fill in the blanks about precipitation.
   
   
   1.  Precipitation falls in 3 main forms: _____________ (liquid), ________________ and ________________ (solids).
   2. The state of matter of precipitation depends on the ___________________. 
   3. In order for water to freeze, it must be below ___________ °C, ___________ °F.

3. Why is sublimation not abundant in nature? What makes it so unique, compared to evaporation, condensation, freezing and melting?

4. Describe how water changes from one state to another.

Answer Key/Rubric

1. Answers as follows:

1. Evaporation l → g
2. Condensation g → l
3. Freezing l → s
4. Melting s → l
5. Sublimation s → g

2. 
   
   1. Precipitation falls in 3 main forms: rain (liquid), hail and snow (solids).
   2. The state of matter of precipitation depends on the temperature
   3. In order for water to freeze, it must be below 0 °C, 32°F.

3. Acceptable responses might include, but are not limited to:

• Sublimation is the change of solid → gas.
• It is unique because it does not turn to liquid, and “skips” a phase of matter.
• Sublimation occurs in the low relative humidity and dry winds. Sublimation also occurs more at higher altitudes, where the air pressure is less than at lower altitudes.

4. Acceptable responses might include, but are not limited to:

• Freezing is when water, in liquid form, turns into ice, the solid form, by cooling the temperature to 0°C.
• Melting is when the ice is heated and turns into liquid water.
• When water vapor is turned back into liquid water it is condensed.
• When liquid water is heated to 100°C it evaporates into water vapor.