An average snowfall yields 1 inch of water for every 10 inches of snowfall. Dense snow contains a larger quantity of water in proportion to its size than lighter density snow. Snow density is affected by the type of storm that produced it, the geographic location and its height above sea level, temperature and air pressure. Give each student a metric ruler and a clear, plastic container to collect snow samples immediately after several winter storms. The container should be filled to the top without compacting it and leveled off with the ruler. Have the students determine if the snow is dense or light and fluffy. Weigh the snow, subtracting the weight of the container. Measure the height of the snow in the container, go indoors to let the snow melt and measure again.
Water freezes at 32-degrees Fahrenheit. Guide your students in an experiment to see how the temperatures of snow, melting snow and water compare. Each child needs a clear cup and a thermometer. Have the students fill the cup with snow, put the thermometer in the snow and record the temperature. The students should take their cups indoors, allow them to sit for five minutes and record the temperature. Have them take and record the temperatures again five minutes later and another five after that. Discuss the freezing and melting processes.
Have your students examine the shapes of snowflakes by giving each one a piece of black construction paper and a magnifying glass. On several snowy days, take the class outside to capture snowflakes on the black paper. Warn them not to breath on the snowflakes and melt them. Examine the snow in a shady area so the sun doesn’t melt it by heating the black paper. Have them record the date, temperature and type of snowflake: columns, columns capped with plates, dendrites, needles and stars.
Your students can “keep” their snowflakes. For younger students, have them put a piece of glass with duct tape around the edges and aerosol-style hairspray in the freezer until a snowfall. When it’s snowing, spray the glass with hairspray and go outside. Collect snowflakes and return inside. Wait about 15 minutes to let the glass thaw.
Each student should put a plastic bag containing a can of liquid plastic spray, microscope slides and a box with a lid outdoors overnight before an expected snowfall. The materials must be as cold as the snowflakes. Spray a slide with the liquid plastic and keep it protected until you are ready to collect snowflakes. Let snow fall on the slide for a few seconds and put it carefully inside the box. Keep the box of slides outdoors for four hours or until the liquid plastic has hardened. Bring the slides indoors and allow the snowflakes to melt. The hardened plastic preserves the details of the snowflakes. Have the students examine the snowflakes under a microscope.