Every four years something funny happens with our calendars -- we add a day! Why do we do this? Discover the science behind leap year.

Learn all about light refraction by simply placing your pencil in a glass of water. Warning: your pencil may not be quiet the same afterward.

What is the water cycle? We're glad you asked! Learn about this amazing natural system that's been working for billions of years.

Learn how energy changes forms with this fourth- and fifth-grade physical science worksheet!

Get charged up about static electricity with this informative fourth- and fifth-grade worksheet!

Become an energy investigator in this electrifying science worksheet!

Energy is a crucial part of physical science! All things on Earth have energy, whether it's potential or kinetic.

Learn about drag, air resistance, and Newton's laws with this cool worksheet on bobsled physics!