Chemistry study guides

Short, accurate explainers on the ideas behind the periodic table — written to pair with the interactive table and the per-element reference pages. Start at the top if you're new; each guide stands alone if you're cramming one topic.

• How to read the periodic table

  Periods, groups, blocks, and what every tile tells you — the 10-minute orientation.

• Periodic trends explained

  Electronegativity, atomic radius, and ionization energy — which way they go and why.

• Metals, nonmetals & metalloids

  The three big classes of elements and the staircase line that separates them.

• Electron configuration, step by step

  How to write and read configurations, noble-gas shorthand, and the famous exceptions.

• Element families: a tour of the groups

  From explosive alkali metals to aloof noble gases — what each column has in common.

Want a specific element instead? Browse the index of all 118 element pages.