Many science concepts can be demonstrated using simple ingredients that you probably already have in your pantry. For example, pull out ingredients for a cake you want to make. Ask your child questions, such as Where do these ingredients come from? Many kids will know milk comes from cows, but where does flour come from? Have your child touch the ingredients and describe the texture: hard, soft, bumpy, squishy, etc.
Then teach your child about the changes in states of matter. Explain that when ingredients are put together, they make a mixture. The cake batter starts off as a liquid but turns into a solid after it is heated in the oven.
Kids can also explore sound and pitch by hitting different sized pans or containers. Put various items, such as rice, pasta, or marshmallows, inside the containers to hear different sounds.