Teaching & Learning
Ducksters Science Biology, Earth Science, Chemistry, Physics, Astronomy, Animals and Environment
Exploratorium Explore, Play, Discover
How Stuff Works Great content (but lots of ads)
NASA Space Place Earth, Sun, Solar System and Universe, as well as Science and Tech
National Geographic for Kids Links and videos of a variety of science topics
Nova Videos and Articles of the PBS show (geared toward older students)
Wonderopolis Where natural curiosity and imagination lead to exploration and discovery in learners of all ages.
WORLDOMETERS Provides counters and real-time statistics for diverse topics.