At this site from the Massachusetts Institute of Technology, you can read about the inventor of "Heavy Water," Gilbert Newton Lewis, who is "one of the most influential and admired scientists of the twentieth century."

This lesson will define ionization energy. It is 2 of 3 in the series titled "Ionization Energy."

This lesson will define ionization energy. It is 3 of 3 in the series titled "Ionization Energy."

This resource offers a brief description of the Octet rule, along with a quick practice, and answers to the exercise.

This lesson will demonstrate how to write the electron configurations for any element given its location on the periodic table. It is 3 of 3 in the series titled "Writing Electron Configurations."

This lesson will point out the difference between electron pairs and unpaired electrons in an atom using orbital diagrams. It is 2 of 3 in the series titled "Paired and Unpaired Electrons."