In this activity, experiment with melting ice using salt and liquid watercolors/food coloring. When salt is generously applied to a large piece of ice, it begins to crack and melt. When coloring is added, the fissures, cracks and tunnels the ice become very “clear”! We see ice melting and refreezing all the time on Earth, and we can even see it happening on other worlds in our Solar System!
-Plastic/glass container or medium-sized bowls (for making the ice)
-Liquid watercolors OR food coloring
-Table salt (fine or coarse)
-Large tray or bin lid (clear or white is best)
-Small jars or cups for liquid watercolors/food coloring
-Spoons OR pipette/dropper (optional)
-Turkey baster (optional)
Step 1: Fill several bowls/containers with water and place overnight in freezer (fill at least ¾ full).
Step 2: Remove ice from freezer. To remove, run warm water over the ice and gently place on tray/bin lid (a large, flat surface like a kitchen table works best for this). Add an old towel or plastic drop cloth for extra protection.
Step 3: Pour some table salt into a bowl. Then, sprinkle some salt on each of the “ice domes.” Start with a small amount, since a little salt can go a long way!
Step 4: The salt should begin to melt the ice after a few minutes. Once you begin to see small rivulets of water, add small amounts of liquid water color to the top of the ice domes with your dropper or spoon (separate your colors into small jars/cups for easy access). For younger kids, it may take some practice to use the droppers.
Step 5: Note where the colors are pooling/running on the ice. Add more salt and color as necessary. Try adding more salt and color in one location on the ice to see what happens.