Yay! It’s fall and soon the leaves will be changing and turning brilliant shades of yellows, reds, and oranges! I can’t wait but until then, we can totally try out fall leaf theme activities like this salt crystal science project perfect for students. Growing salt crystals is a really fun and simple kitchen science experiment you can do either at home or in the classroom.
HOW TO MAKE SALT CRYSTALS?
What’s the science behind this simple salt experiment? A supersaturated solution!
A supersaturated solution is a mixture that can’t hold any more particles. Like with the salt here, we have filled all the space in the water with salt and the rest is left behind.
Water molecules are close together in cold water, but when you heat the water up, the molecules spread away from each other. This is what allows you to add more salt to get that supersaturated solution. It even appears cloudy.
Try this experiment with cold water to compare the differences in the amount of salt needed to get a supersaturated solution. Compare the results of the crystals afterward.
- Construction paper
- Plate or Cookie Tray
STEP 1. Cut out leaf shapes from paper. You can even use a cookie cutter or freehand your designs! Maybe trace leaves you find outside for an added art project and nature walk.
NOTE: You can turn these leaves into ornaments by punching holes into the tips before you crystallize them.
STEP 2. Boil 1 cup of water and add enough salt to over-saturate the mixture. (I always stop when crystals start forming on the surface of the water)
Alternatively, you can use the microwave to heat your water and add salt afterwards. You can heat 1 cup for 2 mins and then stir in one tablespoon of salt at a time.
STEP 3. Put the leaves on a plate with space between each one.
BEFORE you pour the solution, move your tray to a quiet location that won’t be disturbed. It’s easier than trying to do it after you have added the liquid. We know!
STEP 4. Pour a thin layer of saltwater solution over the leaves!
STEP 5. Let your salt crystal leaves sit until the water evaporates. MAKE SURE TO EXAMINE the leaves along the way and check out the crystal growth!
STEP 6. Let dry completely on paper towels if necessary and enjoy!
Make sure to leave out a magnifying glass for your students to explore close up what the crystals look like!