When New York City is frosted in white flakes, fire hydrants and trash piles erased, the boundaries between sidewalks and streets blurred into a vast whitescape, it is impossible not to feel the glittering romance of winter. It’s little wonder that the falling flakes trump my best-laid lesson plans, as frost fever takes over. (Frost fever is cousin (though the polar opposite) of the spring fever we’ll combat in a few months, with symptoms including excessive window-staring and whispered plans about snowball scrimmages at dismissal time.)
While you may not be able to take your students outside to actually play in the snow (although I always try to — it’s incredibly fun!), here are four scientific ways you can bring snow-play into your classroom. (Note: If you haven’t had a recent snowfall in your neighborhood — or any snow at all — you can do most of these activities with ice cubes instead. And the “faux snow” fourth activity is just for you!)
This experiment explores a key principle of science — that matter (and thus mass) is neither created nor destroyed during chemical or physical reactions. This may sound like highfalutin’ science, but it’s actually a simple, observable “law” that even young students can understand. (YouTube has tons of detailed scientific explanations of the law of conservation of mass. I particularly like this historical reenactment during which Antoine Lavoisier “discovers” the conservation of mass.)
For this experiment, your students will test what happens to the mass of a snowball — or an ice cube — when it melts from a solid into liquid water. Will the mass increase or decrease? (Of course, in a closed system, the mass stays exactly the same, but my students don’t necessarily expect that.)
You just need some small sealed containers (takeout containers work well), small snowballs or ice cubes, a heat source (the classroom radiator suffices), and a scale or balance. Students pop their snow or ice into a container and seal it. Then they weigh the container. After the snow completely melts into liquid water, they weigh the container again. If their system is truly closed (the lid stays on the container, they don’t spill the water, etc.) the mass/weight should be the same both times.
Tip: There may be condensation on the outside of the container after the snow melts. This will add a small amount of mass to your closed system, so you’ll want to wipe the condensation off — this is not water from the snow inside, it’s condensed water vapor from the air outside the container. For older students, this makes for a great discussion and drives home the concept of a closed system.
This lab template works well for upper elementary classes. Print the two pages back-to-back, and fold the lab booklet in half to make a pamphlet. My students glue this into their interactive science notebooks.
Your students may already know that salt helps to melt ice. (In fact, salts lower the freezing point of water.) If they haven’t experienced this firsthand, you may want to begin by having them test how much snow or ice melts in a couple of minutes, both with and without the addition of salt.
A student sketches the procedure he will follow to test what happens when melting ice with salt.
Here are the results of the "Salt as an Ice Melt" test. They weighed the liquid water after three minutes of melting.
After your students have experimented with regular table salt, discuss the environmental concerns of using salt outdoors. I share some articles about cities trying to find alternatives to salting their roads such as "How Beet Juice Is Helping Keep Roads Safe This Winter " (Time), "Why Pickle Brine Is a Secret Weapon Against Ice" (National Geographic), or "Fighting Ice With . . . Cheese?" (Scholastic News). Then I challenge my students to test and develop alternative ice-melt solutions that are as effective as salt.
Students plan their experiment in their notebooks and list all of the possible ice melt materials they may test.
Will Kool-Aid or coffee powder help to melt the ice? They tested many, many possibilities!
My students brought in a wide range of ice melt possibilities from home to test with their lab partner friends. They chose whether to test their ice melt inventions on regular ice cubes or on cups of snow. They compared how much snow melted into liquid (by weight) after five minutes with their ice melt solutions as compared a control without an ice melt.
This ice melt experiment became a great science display for the hallway!
This tasty science/cooking activity is always a favorite in my classroom! Here is my time-tested recipe and directions for making individual baggies of homemade ice cream.
I keep the ingredients simple: milk, sugar, condensed milk, and vanilla. I pre-measure all of the ingredients into small cups for the students, and they simply combine the ingredients in their sealable bags.
Cups with pre-measured ingredients speed this activity along with less mess.
Tips: This project can get messy and involves a lot of prep work to prepare the individually portioned ingredients. Recruiting parent volunteers makes this activity a lot more manageable! Also, make sure to double-bag the students’ ice cream mixtures or you’re likely to have leaks.
Tossing around their coffee cans filled with snow or ice, salt, and their baggy of ice cream mixture is a highlight of the experience. It may even beat eating the ice cream!
While all of the previous three experiments work well with ice if you don’t have snow available, sometimes kids just need a dose of the white fluffy stuff. If Mother Nature doesn’t provide, you can buy some inexpensive fake snow to amaze your students with the power of polymers. Faux snow is made from a non-toxic polymer, sodium polyacrylate. This is the same super-absorbent material that’s in baby diapers and gardening “water crystals.” It absorbs about one hundred times its weight in water as it quickly transforms from a light, dry powder into chilly, fluffy “snow.”
During this chaotic classroom video, you'll see just how exciting it is when the dry faux-snow powder transforms into "snow" in seconds:
While the WOW-factor may be enough for this activity, with older students you can delve into the chemistry of polymers, explore what makes this a physical rather than a chemical reaction, or weigh the powder and water separately and then combined together as “snow” to further demonstrate the conservation of mass, even as volume and density change.
Brand name and off-brand instant snow powders work equally as well. You can buy enough for more than thirty students for about $15. Students only need one tablespoon of powder to make their snow.
For another "Faux Snow" option, check out Lindsey Petlak's blog post "Winter Math and Science Can Be "SNOW" Much Fun!" She creates an easy snow substitute with shaving cream and cornstarch.
|Frozen water balloons create a beautiful, nearly magical context for scientific explorations. This works on the coldest of winter days, or as a cool-off activity on a sweltering day. For more ideas about teaching with ice balloons, see my blog post "Asking Questions Like a Scientist: An Ice Balloon Exploration."|
|Meghan Everette shares a wealth of snowman-themed science and literacy ideas in her blog post "States of Matter: Engaging Students With Snow and Science." Her students observed an ice balloon snowman melt over the course of a day, they built goopy snowmen using a dough made of conditioner and cornstarch, and they crystallized pipe cleaner snowmen with a Borax and water solution!|
Why does ice float in liquid water? Will a snowball float or sink? Explore these and other questions with this lab from the University of Chicago Center for Astrophysical Research in Antarctica. In this experiment, students measure and calculate the densities of ice, snow, and liquid water.
Blogger Stacey Burt recommends the ice and snow density experiment, as well as several other snowy activities in her post "Snow Day! Science Activities with Leftover Snow and Ice."
Study the beauty of individual snowflakes with a selection of fabulous science picture books such as The Story of Snow: The Science of Winter's Wonder by Mark Cassino or The Secret Life of a Snowflake: An Up-Close Look at the Art and Science of Snowflakes by Kenneth George Libbrecht.
Then make beautiful three-dimensional paper snowflakes using Genia Connell's detailed directions.
|For younger students (or kids who are bored at home) a bowl of snow and diluted food coloring is all you need for artsy-science fun. I've also filled spray bottles with water and food coloring and let my students explore color mixing outside in the snow.
|For general background about tackling classroom science experiments with limited supplies and time, check out my blog post "Becoming Ms. Frizzle: Managing Classroom Science Lessons."|