ElementsWhere to start
If the periodic table is new to you, begin with the guide on how to read it: what the numbers in each box mean, and what rows and columns tell you. The guide to electron shells then explains why the table has the shape it has, and the guide to trends shows how size, reactivity and other properties change in a regular way across a row and down a column. Those three together cover most of what school courses ask about the table.
For quick revision
The symbols that do not match the English names, such as Na, K, Fe and Au, are a favourite examination question, and they have a guide of their own with the old name behind each. The discovery timeline puts all 118 elements in order of the year they were found, which is a good way to see how chemistry itself grew.
Real values, not just rules
Each guide uses actual figures from the table on this site, so a trend is shown with the numbers that prove it. When you have read a guide, test yourself with the symbol quiz, sort the full list by any property, or open the records page to see which element is the densest, the lightest or the hardest to melt.