On the periodic table, metals are found on the left and in the middle, and non-metals are on the right. A zig-zag line divides them. In most periodic tables hydrogen (H) is shown separately but is ...

At the heart of our biological composition are four elements: oxygen (O), carbon (C), hydrogen (H) and nitrogen (N ... These are almost one-quarter of the periodic table and are mainly found ...

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 ...