World 1 · Atoms & Bonds · 7 minReading the periodic table
Groups, periods and trends
Teaching this? Open projector mode
The periodic table is chemistry’s master map. Every element sits in a box showing its symbol and atomic number, and the layout is not random — elements are arranged so that those with similar behaviour line up.
A vertical column is a group — its elements share a chemical personality. Group 1 (the alkali metals) are soft and violently reactive; Group 18 (the noble gases) are almost inert. A horizontal row is a period, across which properties shift gradually from metal to non-metal.
Reading the table is a superpower: knowing an element’s position tells you roughly how it will bond, what charge its ion prefers, and which elements it will behave like — before you ever run a single experiment.
Elements in the same vertical group tend to…