In this video excerpt from NOVA's "Hunting the Elements," New York Times technology columnist David Pogue investigates chemical reactions involving sodium. Find out how the electron configuration of ...

The chemical formula of a covalent molecular substance gives the number of atoms per molecule. The formula of a covalent network or ionic compound gives the simplest ratio of atoms/ions in the ...

Performing chemical bonding analysis of the Na2He compound, chemists note previously undetected features and predict that, by adding oxygen, a similar compound can be created. Can helium bond with ...

Chemical reactions make new chemicals. Atoms are rearranged during a chemical reaction, but the number of atoms does not change. Evidence of chemical reactions includes a large temperature change, ...

Want to learn more about this centerpiece of chemistry? Take your pick from this collection of links about elements and the periodic table! Build an element ball, solve periodic puzzles, and check out ...