Salt Crystals Experiment

This salt crystals science project is a fun and easy science experiment for kids, perfect for home or school. Every time we grow a new batch of crystals, whether they are salt crystals or borax crystals, we are always amazed by how cool this type of science experiment is to do! Not to mention how easy it is as well!

Salt Crystals Experiment

Here we went with an Easter egg theme for our salt crystals. But you could use paper cutouts of any shape or even string or pipe cleaners suspended in the solution.

Supplies:

• Construction Paper
• Water
• Salt
• Container and Spoon {for mixing salt solution}
• Tray or Plate
• Hole Puncher and String {optional if you want to hang them when you are finished}

Instructions:

STEP 1:  Start by making as many cut out shapes as you would like. Or you can just make one giant shape if you prefer that fills your tray. You will want the shapes to lay as flat as possible, so we used a cookie tray.

At this point, go ahead and punch a hole in the top of the paper cutouts if you plan to use your salt crystals as an ornament!

Also check out how we have done this with paper leaves, snowflakes, gingerbread men and hearts for different themes!

STEP 2:  Place your cutouts on your tray, and get ready to mix your super saturated solution (see below).

STEP 3. First you need to start with hot water, so this is an adult only step if needed.

We microwaved about 2 cups of water for 2 minutes. Though you can see from the above right photo, we did not use all of our solution for our tray.

STEP 4. Now, it’s time to add the salt. We added one tablespoon at a time, stirring very well until completely dissolved. You can feel the point at which it’s not gritty as you stir. {Close to 6 tablespoons for us}

Do this with each tablespoon until you can’t get rid of that gritty feeling. You will see a bit of salt on the bottom of the container. This is your super saturated solution!

STEP 5. BEFORE you pour the solution onto your paper shapes, 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!

Go ahead and pour your mixture over the paper just covering them with a thin layer of the solution.

The more solution you pour over, the longer it will take for the water to evaporate!

You can see that our egg cutouts had a bit of a tough time staying separated and we didn’t try to fix it too much. You could experiment with different methods like tape to stick them down first or an object to block their movement.

Now you just need to give it time to form the salt crystals. We set this up mid-morning and started seeing results by late evening and definitely the next day. Plan to allow approximately 3 days for this activity. Once the water has evaporated, they will be ready.

Borax Crystals are ready faster if you need a quicker crystal growing activity!!

How To Grow The Best Salt Crystals

To make the best crystals, the solution has to cool slowly. This allows the forming crystals to reject any impurities that are also caught up in the solution. Remember, the crystal molecules are all the same and are looking for more of the same!

If the water cools too quickly, the impurities are trapped, creating an unstable, misshapen crystal. You can see that here when we tried to use different containers for our borax crystals. One container cooled slowly and one container cooled quickly.

We transferred our salt crystal covered egg cutouts to paper towels and let them dry out for a while. Plus, the crystals really seem to bond nicely as everything dries out more.

When they are nice and dry, add a string if you wish. Examine the salt crystals with a magnifying glass too. You can explore one single crystal as well like we did below.

These crystals are so cool and they will always be cubed shaped whether they are by themselves or in a cluster. This is because a crystal is made of molecules that come together in a repeating pattern. Check out our single crystal above!

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