General Properties

Chemistry: Cambridge International A Level, topic 2.4.1

The Transition Metals

The transition metals have a set of properties which are characteristic of them.

The transition metals are not just the metals in the d-block. The final triad of the d-block (Zn, Cd, Hg) are not usually thought of as transition metals.
This is because they have a full d sub-shell. D orbitals are clover-shaped.
The transition metals share their properties, and these properties come about because of a partially filled d sub-shell.

The transition metals are metals. This means they have the usual metal properties:
Hard.
Sonorous (ring when hit).
Shiny.
Good electrical conductors.
Good thermal conductors.

The ions of the transition metals have properties which are NOT shared by other metals:
They have multiple oxidation states.
They form coloured ions in solution.
They are often great catalysts for chemical reactions.
They form complexes with ligands (we’ll explain next what that means).

A ligand is a molecule which forms a dative bond with a transition metal.
The ligand donates a lone pair to the transition metal ion.
An ion with ligands attached to it is called a complex ion.
We define the co-ordination number of an ion as the number of dative bonds between a metal ion and its ligands.

Transition metals have high melting points. They generally have higher melting points than s-block metals like calcium.
- This is because there is delocalisation of s and d orbital electrons in transition metals. This gives stronger metallic bonding.
Transition metals are also very dense. They have higher densities than s-block metals like calcium.
This is because as you go across (left to right) the periodic table, the metallic radius of transition metal ions decreases. This is accompanied by an increased atomic mass.