Where they are
- The transition metals are in the central block of the periodic table, between groups 2 and 3.
- Examples include chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni) and copper (Cu).
Compared with group 1
- Transition metals have higher melting points (except mercury), higher densities, and greater strength and hardness.
- They are much less reactive: they do not react as vigorously with water or oxygen.
Typical properties
- Many transition metals form ions with different charges, for example iron forms Fe²⁺ and Fe³⁺, and copper forms Cu⁺ and Cu²⁺.
- They form coloured compounds: for example copper(II) compounds are often blue, and iron(II) compounds pale green.
- Many are useful as catalysts: iron in the Haber process for making ammonia, and nickel in making margarine by hydrogenation of vegetable oils.
Key terms
- Transition metal
- A metal from the central block of the periodic table, such as iron or copper.
- Catalyst
- A substance that speeds up a reaction without being used up.
- Density
- Mass per unit volume.
- Coloured compound
- A compound, often of a transition metal, that has a distinctive colour.
- Haber process
- The industrial process for making ammonia, which uses an iron catalyst.
- Ion
- A charged particle formed when an atom loses or gains electrons.