The periodic table is a chart showing all the elements, the building blocks of the matter around you. If there’s one thing people remember from chemistry class, it’s the periodic table.
Something that is periodic repeats at regular intervals. The periodic table shows how chemical properties are periodic — that is, they reoccur in different elements according to regular patterns in nature. Sure, the periodic table may look like a confusing, somewhat lopsided grid, but now you know there’s a method to the madness.