Learning Outcome:
Students will understand the process of physical weathering from frost action. This lesson would be part of a larger study on types of rocks, and weathering.
Background:
This is one part of a lesson on weathering, looking only at one form of mechanical weathering.
Images used:
https:// wikimedia.org/wikipedia/commons/0/09/Physical_weathering_of_volcanic_rock.jpg
http://cafreetextbooks.ck12.org/science/CK12_Earth_Science_rev.pdf
Video:
Freezing water expanding. (n.d.). Www.youtube.com. Retrieved February 20, 2022, from https://www.youtube.com/watch?v=gdzR17e2MCo
Online Lesson:
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Physical Weathering Part 1
Have you ever looked at rocks, and wondered how they have become broken up? Examine the photo on the right. The rock seems to be breaking into smaller pieces by itself. What can be causing this?
Examine the graphic below. 
First, temperatures need to be above freezing, as liquid water is needed to begin the process. Liquid water runs into the crack in the rock. As temperatures drop, the liquid water turns to ice. During this physical change, the water expands. This expansion of the water is what breaks apart the rock. Higher elevation and northern areas of the world experience more freeze/thaw cycles than other parts. Are there places nearby that you can think of that would experience many freeze/thaw cycles?
Watch the YouTube video Freezing Water Expanding
Have you ever put a can of soda or a water bottle in the freezer? Have you left it there accidentally? What happened or what do you think might happen?
What are three inquiry questions you can think of about the Freeze/Thaw cycle?
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