Chemistry of the d-block transition metals

General Characteristics of d-block Transition Metals

Transition metals are known as d-block elements, as their last electron enters the d-orbital.
These metals demonstrate a range of oxidation states due to the availability of both 4s and 3d electrons in bonding.
They have high melting and boiling points as a result of strong metallic bonding.
They are known for their high density and hardness and exhibit magnetic properties.
Many are good conductors of heat and electricity due to delocalised electrons.

Colour and Coordination Compounds

Transition metals and their compounds often exhibit vibrant colours, which are a result of d-d electron transitions.
They form complex ions with ligands which donate a pair of electrons to the central metal atom to form a coordinate bond. Compounds of this type are called coordination compounds.
They can form both octahedral and tetrahedral complexes; the shape depends on the size and charge of the ligands.
Examples include [Fe(H2O)6]2+ and [CuCl4]2-.

Redox Reactions and Catalytic Activity

The variable oxidation states allow transition metals to undergo redox reactions which are reactions involving reduction (gain of electrons) and oxidation (loss of electrons).
Catalysts lower the activation energy of a reaction and speed up the reaction rate. Transition metals and their compounds often act as catalysts, both in the industry and in the body.
The catalytic activity is attributable to their ability to change oxidation state.

Reaction with Water and Acids

Transition metals typically do not react with water or acids as readily as alkali metals do.
However, some exceptions exist. For example, chromium and manganese react with acids to produce hydrogen gas and the corresponding salts.

Remember to focus on understanding the key concepts and properties of d-block transition metals, including their unique physical traits, reactivity, and behaviour in various chemical reactions.