Investigating Precipitation: Snow

Holly Hansen, Eden Valley- Watkins Elementary School, Eden Valley,MN
Author Profile

Summary

In this chemistry field/class based activity, students investigate snow and, more specifically, why snowflakes have six sides. Students will individually fossilize a snowflake and observe similarities and differences with other members in the class. Students will develop a testable question about the formation of snowflakes, and will learn about the water molecule bonds that form the hexagonal symmetry of a snowflake.

Used this activity? Share your experiences and modifications

Learning Goals

This activity is designed for students to develop critical thinking skills about the world around them. Students will develop their observation and questioning skills while creating a testable question. Students will understand different scientific process through a variety of inquiry based investigations.
Through this activity students will understand water's molecular structure and hydrogen bonds at a very basic level. They will recognize that snowflakes have six sides because of the bond's hexagonal nature.

Context for Use

This activity is designed for a fourth grade class of approximately 20 students. The start of this investigation is dependent on snowfall. It will take at least 4 half hour class segments. This is a development of precipitation for our weather/climate study. The introduction needs to take place during a snowfall, but could develop the rest of the lesson without it if necessary.

Description and Teaching Materials

Day 1- Fossilize a snowflake.
Students will need to dress appropriately for outdoor lab. Each student will receive a small piece of transparency paper (about size of a credit card). Teacher will spray clear finish Krylon on paper outside (spray must be kept in freezer overnight or longer). Student will then "catch" a falling snowflake. Snowflakes will be kept under a box outside to set/dry.

Day 2-
Examine snowflakes with hand lenses. Observe similarities and differences with other students. Teacher will help lead to the question "why does every snowflake have six points?" Read the story "Snowflake Bently" by Jacqueline Briggs Martin.

Day 3-
Discuss the properties of water molecules. Build water molecules with colored marshmallows and toothpicks.

Day 4-
Make a Borax snowflake. Use boiling water and make a saturated solution with common cleaner Borax in a wide-mouthed jar. Students will create their own six-sided figure out of pipe cleaners to fit inside of the jar. The pipe cleaner design should be suspended in solution by a string attached to a pencil laying across the top of the jar. Leave the project alone overnight and see the development of the crystals on the pipe cleaner.

Teaching Notes and Tips

The fossilizing of the snowflake activity is a bit tricky. Last year I used this activity at the first snowfall and the weather didn't stay below freezing. The Krylon wasn't quite cold enough and the snowflakes only turned out to be partials. Use mittens that can be dirtied with the spray and only use in well ventilated area. This study of snow is a lot more in depth than I have done in the past. I used the snowflake story, but never studied the reason why there were six points in a snowflake. I didn't go into the water molecule construction and making the crystals in a snowflake form.

Assessment

Students will be assessed by teacher observation, recording findings in science journals and by end of unit test. Whole class discussions will also be used to assess understanding as well as models and fossils created.

Standards

4.3.2.3.1 Earth and Space Science
4.2.1.2.2 Physical science

References and Resources