Kids love chemistry experiments. And it is so easy to impress them demonstrating kitchen science using some simple foods. Red cabbage juice is a nice pH indicator and it turns to certain colour if you add different foods to it.
All you need is red cabbage, water and all sorts of different food ingredients you can find in your kitchen. The easiest way to impress a young scientist is to use baking soda and vinegar that are found in every kitchen. Just let them experiment with everything they can find and enjoy time together.