As part of our solids and liquids unit we made oobleck which has properties of both a liquid and a solid depending on how much pressure is applied. If you push on it quickly or try to form a ball it acts like a solid, but as soon as you stop pushing on it, it flows like a liquid.
Here's the recipe to make oobleck at home.
Ingredients.
1 1/2 cups corn starch
1 cup water
Food coloring
Pour the corn starch into a large mixing bowl. Add in 3-4 drops of food coloring. Slowly add in the water, stirring as you go. Stop when the mixture is the consistency of honey. Let your child try to pick it up, stir it, and roll it in a ball.
You can also look up videos of kids playing with oobleck to get even more ideas! Don't forget to read Dr. Seuss's Bartholomew and the Oobleck!
Have fun!