It makes sense that a balloon filled with a lightweight gas such as helium would float when surrounded by heavier air. But why does filling a huge balloon with hot air also make it float? This ...

"Quick Tips: Resources for Teachers” is a series of short videos providing down-to-earth advice and instructional tips to teachers of STC™, our signature science curriculum. Each “Quick Tip” offers ...

Same volume, different stuff: the one with more mass = higher density (the metal car is denser than the superball and the water because metal has more mass than the plastic in the superball and the ...

*Refers to the latest 2 years of stltoday.com stories. Cancel anytime. Q Why do some logs float and some sink? — Holden Taggart, Merrimac, Wis. A Rodney Schreiner, chemistry department, University of ...

Water's unique property of ice floating on its liquid form is crucial for life on Earth. This phenomenon, caused by the ...