Element category
Transition metals
The transition metals fill the d subshells across the middle of the periodic table, spanning groups 3 to 12. Partly filled d orbitals let most of them take several oxidation states, form colored compounds and act as catalysts. As a family they are hard, dense, high melting metals and excellent conductors of heat and electricity, with mercury, a liquid at room temperature, as the famous exception.
At a glance
- Elements
- 34
- Atomic numbers
- 21 to 108
- Block
- d-block
- Periods
- 4, 5, 6, 7
- Phase at STP
- solid (28), liquid (1)
Shared properties
- Electrons fill d subshells, so most members show multiple oxidation states
- Many form colored ions and compounds because of d electron transitions
- Typically hard, dense and high melting, with strong metallic bonding
- Widely used as structural metals and as catalysts in industrial chemistry