Transition Metals & Iron

The elements of  ‘d’ block of periodic table including elements of Group IB to vii B. And viii are transition metals some important characteristics of transition metals are

·         They have general configuration (n-1)d1-10 ns1-2 . They have partially filled valence shell and penultimate shell.

·         Transition metals have strong metallic bond, so they are heavy and herd. They have high mpt and bpt.

·         They are highly malleable and ductile they have high electrical and thermal conductivity.

·         They can absorb large quantity of the gases on their surface and this phenomenon is called occlusion. Because of this property these metals are used as catalyst in gaseous reaction.

·         Transition metals show variable oxidation state. For 3d, series, +2 is common O.S.

Eg.             Sc            →        +2 and +3

                        Cu               →    +1 and +2

                        Mn           →        +2,+3,+4,+5,+6 and +7

 MnSO4, Mn2O3, Mno2, Mn2o5, K2Mno4/HMno4

·         Transition metal forms colored compounds. The color of compounds is determined by number of unpaired electrons in d-orbital species with some no of unpaired electrons have same color.

Eg. V4 +              →         Cu4

(Ar)3d1            →            (Ar)3d9                        both have blue color.

 1 Unpaired e+             1 unpaired e

·         They transition metal and metal ions show paramagnetic nature. The magnetic moment depends upon the number of unpaired electrons in d-orbital.

·         Transition metal ion can from complex with ligands. The central metal provides empty orbitals into which ligands donate tone pair of electrons forming co-ordinate co-Volant bond.