This is the periodic table of elements. It is arranged in many ways. The periods, or rows, show how many electron shells the element has. The groups, or columns, show how many valence electrons, electrons on the outer shell, the elements have. The elements are also clumped by what kind of metal or non-metal the element is, which is shown by the color of the element. Also, the atomic number of the element increases as you go left to right, top to bottom. Finally, the lanthanoids and actinoids are put on the bottom so the table is more like a square, which is easier to put on a page than a wide rectangle.

The table is not too hard to read. In this layout, there are four things you can learn from looking at the table. To learn what these things are, you can click on molybdenum (number 42) or californium (number 98).