Objective(s):

• Students will be able to describe the relationship between energy and phase changes.

Essential Question(s):

• What is the relationship between energy and phase change?
  

• SC.912.P.10.4 Describe heat as the energy transferred by convection, conduction, and radiation, and explain the connection of heat to change in temperature or states of matter.

Changes in the Phases of Matter

We know that matter on Earth normally exists as a solid, a liquid, or a gas.  Matter can be changed from one phase to another. For example, water can be a liquid. If it is frozen, it will become a solid. Remember that as substances cool they lose heat. This means they lose energy. Ice has less heat energy than liquid water. When water is heated, it can become a gas and form clouds. As substances like water warm up, they gain heat.  Boiling water produces water, gas, or steam. Steam has more heat energy than ice or liquid water. Other materials can be changed from one form to another. When a material melts, it changes from a solid to a liquid. The temperature at which this happens is called the melting point. When a substance reaches its freezing point or boiling point, it also undergoes a physical change from one phase to another, changing some of its physical properties.

Concept Map: Complete the concept map below by adding the appropriate phase and adding a + or - in each of the boxes to illustrate whether energy has been lost or gained.

Draw a concept map describing the three states of matter and include key terms related to phase changes such as evaporation, condensation, solid, liquid, gas, energy gain (+) and energy loss (−).  Use the following map as an example: