Use sand and ice cubes to explore polar regions, climate change, Mars and freezing/melting at Howtosmile.org. Create a model of permafrost and the effects of the ice melting through the surface in the TERC Ice on Mars activity.
Conduct a simple experiment on how temperature changes make things expand or contract at Howtosmile.org. in the Del Monte Vibrating Pennies activity, investigate how heat from your hands warms air in a bottle and lifts a penny sitting on the mouth of the bottle.
Construct possible food webs for six different ecosystems at Howtosmile.org. Learn about producers vs. consumers and different kinds of consumers (herbivores, carnivores, omnivores, decomposers and scavengers) in the Food Webs activity from Baylor College of Medicine.
Use an egg to show why the sky changes color at Howtosmile.org. Discover what makes the sky look blue on sunny days and red during sunrise and sunset, in the Why Is the Sky Purple? activity from Colorado State University.
Why do we need two eyes to judge depth? Find the answer at Howtosmile.org. Compare the accuracy of dropping objects while using only one eye or both eyes, in the Drop IT! activity from University of Washington.
Measure night sky brightness and earn about light pollution and how it can affect energy consumption, wildlife and health at Howtosmile.org. Become a citizen scientist in the Globe at Night activity from the National Optical Astronomy Observatory. Resources available in more than 20 languages.
Act out each function of the digestive tract's organs, tissues, and cells at Howtosmile.org. Simulate peristaltic movement and each element of digestion in the Digestive System: A Kinesthetic Lesson activity from the National Health Museum.
Compare how salt water and fresh water freeze at Howtosmile.org. Experiment to contrast how pond and ocean animals survive cold winters. The activity Ponds Freeze in the Winter—Why Doesn't the Ocean, from the New England Aquarium, covers freezing points and animal adaptation.