Let’s use science and chemistry to make sidewalk chalk! This STEM project for kids is simple, easy, and fun. Afterwards, talk your chalk outside and get creative!
To make your own chalk, you will need:
Plaster of Paris
Let’s get started! (You can view the video instructions here)
Put the plaster in the baggie, filling it a little less than halfway. Pour in the water, about a cup. Take your powder pigment and dump all of it in the bag. Seal the bag, making sure you squeeze out the air. Gently knead the bag to mix all of the ingredients. Continue to mix until it is completely mixed, with no white plaster spots left.
Carefully open a small portion of the bag. Squeeze out your mixture into the silicone mold.
Get rid of the air bubbles and flatten your chalk by gently tapping your mold against the table. You’ll see bubbles rise up, and see the plaster flatten.
It could take anywhere from an hour or a day for your plaster to harden all the way. Just keep checking on it!
Once your chalk has hardened, you can pop each piece of chalk out of the silicone mold. Your chalk is ready to use!
Have fun playing with your DIY sidewalk chalk! The possibilities are endless!