Topic: The d and f-block elements
Group 3-12 elements are called as d-block
elements. These are placed between S and P-block
elements.
For these elements, electrons are progressively added to penultimate d-
subshell (n-1) d.
d-block elements are also called as transition elements.
Meaning of Transition element:
Elements with incompletely or partially filled d-orbitals (d1-d9 configuration) either in
the ground state or in any one of their oxidation states are called Transition elements.
Note: Zn, Cd and Hg are called as non transition elements as they have completely
filled d10 configuration in their atomic state and in their common oxidation states of +2.
Transition elements include Precious metals; Ag, Au, Pt and industrially important
metals: Cu, Fe,Ti.
The f-block elements:
In the elements constituting the f-block, the 4f and 5f-orbitals are progressively filled.
These are formal members of group-3, hence they are also called as inner transition
elements. On account of their different properties, they have been taken out from d-
block and are kept separately at the bottom of the periodic table.There are two series of
f-block elements
4f series of elements (are called Lanthanoids).
5f series of elements (are called Actinoides).
The Transition Elements (d-block elements)
Electronic configuration:
General electronic configuration: (n-1) d1-10 ns1or 2 (n=4,5,6,7)
Classification of Transition elements based on progressive addition of elec-
trons into d-subshell
There are 3 series of transition metals:
3d series (I transition series),
4d series (II transition series),
5d series (III transition series),
6d series (IV transition series)
Type of series Ele.Confign Elements
3d series 3d1-10 4s1or 2 Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn.
(I transition series) (At.number from 21 to 30)
4d series 4d1-10 5s1or 2 Y, Zr, Nb, Mo, Tc, Ru, Rh, Pb, Ag, Cd
(II transition series)
5d series 5d1-10 6s1or 2 La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg.
(III transition series)
6d series 6d1-10 7s1or 2 Ac, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn.
(IV transition series)
,
, In d-block elements, ’s’orbital is outermost orbital and it is filled with one or two elec-
trons and electrons are added progressively in penultimate shell ,i.e., (n-1) d orbital.
In Cr and Cu-group elements, S-orbital contains one electron on account of
extra stability of half filled 3d54s1 and fully filled 3d104s1 orbitals.
This happens due to very less energy gap between (n-1) d and ns orbitals.
Electronic configuration of Zn-group (Zn, Cd, Hg) = (n-1)d10 ns2
These elements are often not considered as transition elements as they contain
completely filled d10 configuration in both ground state as well as in their common +2
oxidation state: (n-1)d10 ns0.
It is found that in transition elements there is greater similarity in properties along the
period than in group, however, some group similarities also exist.
Transition elements exhibit variety of properties:
Transition elements are well known for their following properties.
Variable oxidation states.
Catalytic properties.
Formation of coloured compounds.
Formation of Co-ordination complexes.
Magnetic properties.
Formation of interstitial compounds.
Formation of alloys.
General properties of transition elements
Physical properties:
Transition elements are typical metals; they possess high tensile strength, ductility
and malleability. They have good thermal and electrical conducting capacity.
They are crystallized into definite crystal lattice and posses definite crystal lattice.
They are hard, (except Zn, Cd, Hg) have high melting and boiling points.
High melting point of metals is due to Strong metallic bonding (M-M bonding)
or Strong interatomic forces
Strong metallic bonding is due to presence of more number of unpaired electrons in
d-orbital.[explained on basis of involvement of greater number of electrons from (n-1)d
and ns electrons in metallic bonding(M-M).
Melting point of transition elements raises to a maximum at d5 configuration, except
for Mn, Tc which has unexpectedly less melting point.
Group 3-12 elements are called as d-block
elements. These are placed between S and P-block
elements.
For these elements, electrons are progressively added to penultimate d-
subshell (n-1) d.
d-block elements are also called as transition elements.
Meaning of Transition element:
Elements with incompletely or partially filled d-orbitals (d1-d9 configuration) either in
the ground state or in any one of their oxidation states are called Transition elements.
Note: Zn, Cd and Hg are called as non transition elements as they have completely
filled d10 configuration in their atomic state and in their common oxidation states of +2.
Transition elements include Precious metals; Ag, Au, Pt and industrially important
metals: Cu, Fe,Ti.
The f-block elements:
In the elements constituting the f-block, the 4f and 5f-orbitals are progressively filled.
These are formal members of group-3, hence they are also called as inner transition
elements. On account of their different properties, they have been taken out from d-
block and are kept separately at the bottom of the periodic table.There are two series of
f-block elements
4f series of elements (are called Lanthanoids).
5f series of elements (are called Actinoides).
The Transition Elements (d-block elements)
Electronic configuration:
General electronic configuration: (n-1) d1-10 ns1or 2 (n=4,5,6,7)
Classification of Transition elements based on progressive addition of elec-
trons into d-subshell
There are 3 series of transition metals:
3d series (I transition series),
4d series (II transition series),
5d series (III transition series),
6d series (IV transition series)
Type of series Ele.Confign Elements
3d series 3d1-10 4s1or 2 Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn.
(I transition series) (At.number from 21 to 30)
4d series 4d1-10 5s1or 2 Y, Zr, Nb, Mo, Tc, Ru, Rh, Pb, Ag, Cd
(II transition series)
5d series 5d1-10 6s1or 2 La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg.
(III transition series)
6d series 6d1-10 7s1or 2 Ac, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn.
(IV transition series)
,
, In d-block elements, ’s’orbital is outermost orbital and it is filled with one or two elec-
trons and electrons are added progressively in penultimate shell ,i.e., (n-1) d orbital.
In Cr and Cu-group elements, S-orbital contains one electron on account of
extra stability of half filled 3d54s1 and fully filled 3d104s1 orbitals.
This happens due to very less energy gap between (n-1) d and ns orbitals.
Electronic configuration of Zn-group (Zn, Cd, Hg) = (n-1)d10 ns2
These elements are often not considered as transition elements as they contain
completely filled d10 configuration in both ground state as well as in their common +2
oxidation state: (n-1)d10 ns0.
It is found that in transition elements there is greater similarity in properties along the
period than in group, however, some group similarities also exist.
Transition elements exhibit variety of properties:
Transition elements are well known for their following properties.
Variable oxidation states.
Catalytic properties.
Formation of coloured compounds.
Formation of Co-ordination complexes.
Magnetic properties.
Formation of interstitial compounds.
Formation of alloys.
General properties of transition elements
Physical properties:
Transition elements are typical metals; they possess high tensile strength, ductility
and malleability. They have good thermal and electrical conducting capacity.
They are crystallized into definite crystal lattice and posses definite crystal lattice.
They are hard, (except Zn, Cd, Hg) have high melting and boiling points.
High melting point of metals is due to Strong metallic bonding (M-M bonding)
or Strong interatomic forces
Strong metallic bonding is due to presence of more number of unpaired electrons in
d-orbital.[explained on basis of involvement of greater number of electrons from (n-1)d
and ns electrons in metallic bonding(M-M).
Melting point of transition elements raises to a maximum at d5 configuration, except
for Mn, Tc which has unexpectedly less melting point.
