This video by National Geographic is also a good one (depending on your child's attention span)
This underwater volcano experiment is on our "To do" list tomorrow. Today we watched it over and over again.
I swear we actually left our house and didn't spend the whole day watching videos :)
We also tried out a new-to-us Melissa and Doug paint with water book. I was really excited about it... but the paintbrush was pretty thin and didn't hold enough water, so my little guy got so frustrated! You know a painting session isn't going well when the artist throws the paintbrush across the room!
I did love the variety of painting pages in the book... especially since two of them were dinosaur themed!