Melting and Freezing

http://www.sciencenetlinks.com/lessons.cfm?DocID=161

A lesson plan for Grade 2 Science

Provider: American Association for the Advancement of Science

About this resource

Appropriate grades

2

Subjects

science (chemistry)

Provider

American Association for the Advancement of Science

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The purpose of this lesson is to explore what happens to the amount of different substances as they change from a solid to a liquid or a liquid to solid. Students will investigate how melting and freezing impact the amount of three separate everyday items. Water is the first substance, followed by chocolate, and last margarine.

This lesson is designed to lay the foundation for many critical benchmarks that follow. At this age students should be able to recognize the pattern of liquid to solid and solid to liquid. The students will receive one of their first introductions to the concept of conservation of matter. They will experience that when a substance changes from a solid to a liquid the amount (weight) does not change. This lesson strongly relates to benchmark 4B (K-2) #2: Water can be a liquid or a solid and can go back and forth from one form to the other. If water is turned to ice and then the ice is allowed to melt, the amount of water is the same as it was before freezing. Students will be exposed to a lower level concept that is central to the understanding of the water cycle, that water is able to take many forms but it is still water.

This lesson is designed to help the students prepare themselves for the idea that most substances may exist as solids, liquids, or gases depending on the temperature, pressure and nature of that substance. This understanding is critical to understanding that water in our world is constantly cycling as a solid, liquid, or gas.