Chemical families
Families reveal recurring behaviour in the periodic table. These pages explain what the groups have in common, where the similarities stop and why they matter.
Alkali metals
Lithium, sodium and potassium belong to one of the easiest families to spot in the periodic table. They all have one electron in their outer shell.
Alkaline earth metals
Group 2 includes magnesium and calcium, two elements that are familiar both in materials and in living organisms.
Transition metals
Iron, copper, nickel, silver and gold sit in the broad central region of the periodic table. This is where some of chemistry’s most varied metallic behaviour appears.
Halogens
Fluorine, chlorine, bromine and iodine belong to group 17. They are reactive non-metals with seven electrons in their outer shell.
Noble gases
Helium, neon and argon sit in group 18. Their outer electron shells are complete, which makes them far less reactive than most neighbouring elements.
Lanthanides
The lanthanides form the first detached row below the main table. Their chemistry is very similar, yet their magnetic and optical properties make them extremely useful.
Actinides
The actinides form the second detached row below the main periodic table. Every member of this series is radioactive.
Metalloids
Metalloids sit near the boundary between metals and non-metals. The category is useful, but its exact membership is not defined identically everywhere.