d and f - block elements

2. Infamous Families of the Periodic
Table
Halogen
Noble Gas
Chalcogens
Alkali
1
IA
1
2
IIA
Alkaline
(earth)
• Notable families of the Periodic Table and13 14 important 17
some 15 16
IIIA IVA
VA
VIA VIIA
members:
Transition Metals
2
3
4
5
6
7
3
IIIB
4
IVB
5
VB
6
VIB
7
VIIB
8
9
VIIIB
10
11
IB
12
IIB
18
VIIIA

3. Periodic Table: The three broad
Classes
Main, Transition, Rare Earth
• Main (Representative), Transition metals, lanthanides and actinides (rare
earth)

4. THE TRANSITION ELEMENTS (d-BLOCK
Position in the Periodic Table
groups 3-12 in which the d orbitals are progressively filled
in each of the four long periods.
The elements constituting the d-block are those in which the
d - orbitals are progressively filled (incompletly filled ‘d’
orbitals
The d–block occupies the large middle section flanked by s– and
p– blocks in the periodic table. The very name ‘transition’ given to
the elements of d-block is only because of their position between
s– and p– block elements.
three rows of the transition metals, i.e., 3d,
fourth row of
6d
is still incomplete.
4d and 5d. The

7. Electronic Configurations of the d-Block
electronic configuration (n-1)d1–10
ns1–2
Because of very little energy difference between (n-1)d
and ns orbitals. case of Cr which 3d5 4s1 has instead of
3d4 4s2, Cu which has 3d 10 4s1 instead of 3d9s2

8. Zinc, cadmium and mercury of group 12 have full d10
configuration in their ground state as well as in their
common oxidation states and hence, are not regarded
as transition metals. However, being the end members
of the three transition series, their chemistry is studied
along with the chemistry of the transition metals.
On what ground can you say that scandium (Z = 21) is a
transition element but zinc (Z = 30) is not?
Silver atom has completely filled d orbitals (4d10) in its ground
state. How can you say that it is a transition element?
Various precious metals such as silver, gold and
platinum and industrially important metals like
iron, copper and titanium form part of the transition
metals

9. General Properties of the Transition Elements
(d-Block)
1. Metallic properties such as high tensile
strength, ductility malleability, high thermal and
electrical conductivity and metallic lustre.
2. The transition metals (with the exception of Zn,Cd &Hg)
are very much hard and have low volatility.
3.The d orbitals project to the periphery of an atom more than
the other orbitals & exhibit certain characteristic properties
a) variety of oxidation states,
b) formation of colored ions
c) complex formation with a variety of ligands
d) catalytic property
e) paramagnetic behaviour.

10. Physical Properties
The transition metals (with the exception of Zn, Cd and Hg) are very
much hard and have low volatility. Their melting and boiling
points are high
Involvement of greater number of electrons
from (n-1)d in addition to the ns electrons in
the inter atomic metallic bonding.
melting points of these metals rise to a
maximum at d5 except for anomalous
values of Mn and Tc and fall regularly as
the atomic number increases

11. Trends in enthalpies of atomization of transition elements
1. greater the number of valence electrons, stronger the
inter atomic attraction, hence stronger bonding
between atoms resulting in higher enthalpies of
atomization.
2. metals of the second and third series have greater
enthalpies of atomization than the corresponding
elements of the first series

12. Enthalpy of atomization of zinc is the lowest,
Why?

13. Variation in Atomic and Ionic Size
1.New electron enters a d orbital each time the nuclear charge
increases by unity ,But the shielding effect of a d electron is
not that effective, hence the net electrostatic attraction
between the nuclear charge and the outermost electron
increases and the ionic radius decreases

14. Lanthanoid contraction
1.There is increase from the first (3d) to the second (4d)
series of the elements.
But the radii of the third (5d) series are virtually the same as 4d
2.This is due to the intervention of the 4f orbital which must be
filled before the 5d series of elements begin.
There is a steady decrease in atomic radii from La due to
the poor shielding of inner core electrons (4f) is known
lanthanoid contraction.

15. Ionization
Enthalpies
1. Due to an increase in nuclear charge there is an
increase in ionisation enthalpy along each series of the
transition elements from left to right.
2. Ionisation enthalpies give some guidance concerning the
relative stabilities of oxidation states.
3.Although the first ionisation enthalpy, in
general, increases, the magnitude of the increase in the
second and third ionisation enthalpies for the successive
elements, in general, is much higher.
4. Mostly IE1<IE2 <IE3 in each group

16. Why do IE1 of Cr is less ,but for Zn it is very high
why for Zn IE2 is less
why for Fe IE3 is less , but for Mn it is very high

17. Oxidation States
1.The variability of oxidation states, a characteristic of transition
elements
2.They loose electron from ultimate and penultimate shell.
3.oxidation state differ from each other by 1 unit(Fe+2, Fe+3) ,but
in ‘P’ Block it differ by 2 unit(Sn+2, Sn+4) (due to inert pair effect)
4. In Ni(CO)4 and Fe(CO)5, the oxidation state of nickel and iron
is zero.(In π complex compound)
ANSWER THE FOLLOWING
1. Name the element shows Largest number of oxidation state
2. Titanium (IV) is more stable than Ti(III) or Ti(II)
3. Name a transition element which does not exhibit variable

18. 1.Electrode Potentials value depends enthalpy of
atomization ΔHa & hydration ΔH hyd
2.The E0(M2+/M) value for copper is positive (+0.34V)
high ΔHa and low ΔH hyd)

19. 1.Why is Cr2+ reducing and Mn3+ oxidising when both have
d4 configuration.
2.Cu, having a positive E0, accounts for its inability to
liberate H2 from acids.
4. E0(M3+/M2+)values
a) The low value for Sc reflects the stability of Sc3+
b) The highest value for Zn is due to the removal of an electron
from the stable d10 configuration of Zn2+.
c) Low value for Fe shows the extra stability of Fe3+ (d5).
d) low value for V is related to the stability of V2+ (half-filled t2g
e) The highest oxid. numbers are achieved in TiX4 ,VF5, CrF6
The ability of fluorine to stabilize the highest oxidation state is
due to either higher lattice energy as in the case of CoF3, or
higher bond enthalpy terms for the higher covalent
compounds, e.g., VF5 and CrF6

21. Trends in Stability of Higher Oxidation States
1. copper (I) compounds are unstable in aqueous solution
and undergo disproportionation.
2Cu+ → Cu2+ + Cu
2.highest oxidation state of a metal exhibited in its
oxide or fluoride(as they are more EN)
3.How would you account for the increasing oxidising
power in the VO + < Cr2O7 – < MnO4
2
2

23. MAGNETIC
PROPERTY
PARAMAGNETIC
DIAMAGNETIC
FERROMAGNETIC
1. Diamagnetic substances are repelled by the applied
field while the paramagnetic substances are
attracted, attracted very strongly are
ferromagnetic(ferromagnetism is an extreme form of
paramagnetism)
2. Many of the transition metal ions are paramagnetic.
3. Paramagnetism arises from the presence of unpaired
electrons,
4. magnetic moment of an electron is due to its spin
angular momentum and orbital angular momentum

24. 5. magnetic moment is determined by the number of unpaired
electrons and is calculated by using the ‘spin-only’ formula,
μ =√ n(n+2) n is the no. of unpaired electrons
μ is the magnetic moment in units of Bohr magneton (BM).
A single unpaired electron has a magnetic moment of 1.73BM
6. More the no. of unpaired electrons ,more the magnetic moment.

25. ANSWER THE FOLLOWING
1.Calculate the magnetic moment of a divalent ion in
aqueous solution if its atomic number is 25.
2. Calculate the ‘spin only’ magnetic moment of M 2+
(aq) ion (Z = 27).

26. Formation of Colored Ions
left to right: V4+, V3+, Mn2+, Fe3+, Co2+,Ni2+and Cu2+
•Color is due to excitation and reexcitation of unpaired‘d
electrons.
•The frequency of the light absorbed lie in visible region
•The color observed is the complementary color
•The frequency depends on nature of ligand
•In aqua complexes the color gets intensified

27. Formationof ComplexCompounds
•Metal ions bind a number of anions or neutral molecules
giving complex
[Fe(CN)6]3–, [Fe(CN)6]4–, [Cu(NH3)4]2+ and [PtCl4]2–
.
This is due to the
•Comparatively smaller sizes of the metal ions,
• Their high ionic charges and
•The availability of d orbitals for bond formation.

28. Catalytic Properties
•ability to adopt multiple oxidation states and to form
complexes (the activation energy is lowering)
EXAMPLES
Vanadium (V) oxide (in ContactProcess),
finely divided iron (in Haber’s Process), and
nickel (in Catalytic Hydrogenation)

29. Formation of Interstitial Compounds
when small atomslike H, C or N are trapped inside
the crystal lattices of metals
They are usually non stoichiometric
example, TiC, Mn4N, Fe3H, VH0.56 and TiH1.7
(i) They have high melting points, higher than those of pure
metals.
(ii) They are very hard, some borides approach diamond in
hardness.
(iii) They retain metallic conductivity.
(iv) They are chemically inert.

30. Alloy Formation
Because of similar radii and other characteristics
of transition metals,
The alloys so formed are hard and have often high melting points.
ferrous alloys: chromium, vanadium, tungsten, molybdenum
and manganese are used for the production of a variety of steels and
stainless steel.
Alloys of transition metals with non transition metals
such as brass (copper-zinc) and bronze (copper-tin),