Transition metals are found in the 'd' block of the Periodic Table and all have a partially filled 'd' energy level, either as an atom or an ion. All transition metals have general properties of metals.
Properties of Transition Metals
* High melting point
* High boiling point
* Conductors of heat and electricity
* Relatively high density
* Have catalytic activity
* Form complexes
* Form coloured compounds
* Have variable oxidation states
The first 4 are general properties of metals, however the last 4 are specific to transition metals.
Remember 4s fills before 3d, but it is convention to write them in numerical order.
When forming ions, electrons are lost from 4s first.
s shells have 2 electrons, p shells have 6, d shells have 10
The order we write them in is;
1s 2s 2p 3s 3p 3d 4s 4p 4d and so on.
Chromium and copper fill slightly differently to provide a more stable configuration.
24Cr: 1s2 2s2 2p6 3s2 3p6 3d5 4s1
29Cu: 1s2 2s2 2p6 3s2 3p6 3d10 4s1
A complex ion is formed when transition metals or their ions form co-ordinate bonds with ligands.
Ligands are species that can donate one or more pairs of electrons, and can be an ion or a molecule.