The "Visual Glossary" has many of your vocab words.
Other ways to find definitions:
Britannica Online: School Edition (if you log in at school and use the link on the library's page you will be logged in)
Vocab Menu Links
Quizlet Crossword Puzzle Maker Crossword Puzzle Maker 2 Kahoot
The Life of a Scientist
dragonflyTV (real scientist biographies) PBSlearning (science career profiles)
sciencekids (science career descriptions)
Online Science Magazines
National Geographic Kids (games)
Electric Circuits
Earth, Sun, and Moon