Edible Chemistry Kit
We opened it up the other day and set out to do a few of the experiments provided in the instructions. The kit comes with several experiments that all focus on the same chemistry topic: acids versus bases.
This is probably not the best gift for a kid with chemistry experience, but for the beginning chemist, this is a great, safe approach at testing basic chemistry. I took a few pictures of my daughters' (the 4 year old helped out too) experiments.
The color of the liquid changes depending on how acidic or basic the solution is. My daughters loved this and we still have several experiments left to test. These are great for days the kids are bored and can't go outside due to poor weather.