Question

why does transition metal shows complex compound,alloy formation,act as acatalyst

Answer 1

(1) Transition metal shows complex compound
They form large no. of complex compound due to presence of partially filled d- orbital and their tendency to show variable oxidation state .
(2) Transition metal shows alloy formation.
Alloys are homogeneous solid solutions of two or more metals. These are formed by metals whose atomic radius does not differ much so that the atoms of one metal can easily take up the positions in the crystal lattice of the other.
Transition metals have similar atomic radii and so transition metal of a particular type can be substituted by another from the lattice arrangement of previous thus they can form alloys very readily.
(3) Transition metal act as a catalyst
Transition metals are good catalyst because they contain free valency which work as a platform for other reactant molecule to interact quickly i.e. their ability to change oxidation state or, in the case of the metals, to adsorb other substances on to their surface and activate them in the process.