I like the growing plants with different types of music one.
Or this one may seem kind of dumb,
But measure how much vitamin C that three types of orange juice has.
1. home-ade
2. premium not from concentrate.
3. and some made from frozen concentrate.
it will help you learn how by using a iodine titration method.
I had fun with that one

haha
Or
how fast an alka selzer tablet makes gas
Idk if any of those ideas sound good, but im just happy if i helped!
