SciFri: Sink or Float

Rocks tend to sink, except Mom’s pumice stone!
LEGO floated when they were stuck together and held air inside, but we could make them sink by separating them, filling with water, and holding them just right.
Rubber ducks float, of course, as do apples and pine cones. And plastic dinosaurs too.
But we learned something really super cool about oranges: They will float if they have their peel on, but if you take the peel off, then they sink!!