The D- and F- Block Elements

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The d-block of the periodic table includes group 3 to 12. The elements placed in the group 3 – 12 are called d-block elements. In these elements d-orbitals are progressively filled along with periods. f-block elements have been placed separately at the bottom of the periodic table. The f-block includes those elements in which 4 f and 5 f orbitals are progressively filled.  d-block elements are also called transition elements (or transition metals) and f-block elements are also known as inner transition elements (or inner transition metals).


The D-block Elements or Transition Elements 

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What are Transition Elements? 

Transition elements or transition metals are those elements which have partially filled d-orbitals. Transition elements are also known as d-block elements. Transition elements occur from 21Sc to 112Cn, excluding lanthanides and actinides. Lanthanide and actinides are known as inner transition elements. Transition elements show transition from metals to nonmetals in the periodic table, that’s why given the name transition elements. So, transition elements can be defined as the elements which are placed in between the s-block and p-block elements in the modern periodic table. 

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Properties of Transition Elements

Transition elements properties can be defined by following points- 

1. Transition elements show variable oxidation numbers and many valences. For example Ti shows +3 , +4 valences and Cr shows +2, +3, +4, +6 valances. 

2. These elements form coordination compounds or coordination complexes. 

3. These metals form coloured compounds. 

4. These metals show high melting and boiling points. 

5. These elements have high densities. 

6. These elements show catalytic properties. 

7. These elements generally form stable complexes. 

8. These elements have large charge and radius ratio. 


Transition Elements Series

D-block elements or transition elements are divided into following four series – 

1. First Transition Series 

2. Second Transition Series 

3. Third Transition Series 

4. Fourth Transition Series 

1. First Transition Series – 1st transition series includes elements from Sc to Zn present in the 4th period of periodic table. 

1st Transition Series Elements - 

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2. Second Transition Series – 2nd transition series includes elements from Y to Cd present in the 5th period of periodic table. 

2nd Transition Series Elements - 

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3. Third Transition Series – 3rd transition series includes elements from Hf to Hg present in the 6th period of periodic table. 6th period includes lanthanides also. Lanthanides are known as inner transition elements. 3rd transition series elements - 

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4. Fourth Transition Series Elements – 4th transition series includes elements from Rf to Cn present in the 7th period of periodic table. 7th period includes actinides also. Actinides are also known as inner transition elements.

4th Transition Series Elements – 

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Transition Elements List

Period 

Group 

Element (Symbol) 

Atomic Number 

Electronic Configuration 

4

3

Sc

21

3d14s2

4

Ti

22

3d2 4s2

5

V

23

3d3 4s2

6

Cr

24

3d4 4s2

7

Mn

25

3d5 4s2

8

Fe

26

3d6 4s2

9

Co

27

3d7 4s2

10

Ni

28

3d8 4s2

11

Cu

29

3d10 4s2

12

Zn

30

3d10 4s2

5

3

Y

39

4d1 5s2

4

Zr

40

4d2 5s2

5

Nb

41

4d4 5s1

6

Mo

42

4d5 5s1

7

Tc

43

4d5 5s2

8

Ru

44

4d7 5s1

9

Rh

45

4d8 5s1

10

Pd

46

4d10

11

Ag

47

4d10 5s1

12

Cd

48

4d10 5s2

6

4

Hf

72

5d2 6s2

5

Ta

73

5d3 6s2

6

W

74

5d4 6s2

7

Re

75

5d5 6s2

8

Os

76

5d6 6s2

9

Ir

77

5d7 6s2

10

Pt

78

5d9 6s1

11

Au

79

5d10 6s1

12

Hg

80

5d10 6s2

7

4

Rf

104

6d2 7s2

5

Db

105

6d3 7s2

6

Sg

106

6d4 7s2

7

Bh

107

6d5 7s2

8

Hs

108

6d6 7s2

9

Mt

109

6d7 7s2

10

Ds

110

6d8 7s2

11

Rg

111

6d9 7s2

12

Cn

112

6d10 7s2


Properties of Some Main Elements of D-block 

  • Titanium - Titanium is the 7th most abundant metallic element and 9th most abundant element in the Earth’s crust. It is mostly found as oxides in igneous rocks. It is also found in the lithosphere. Titanium is present in almost all living things, water bodies, rocks and soil. For commercial use titanium is mostly obtained by extraction of ilmenite (FeTiO3) and rutile (TiO2) ores by mainly two processes either Kroll process or Hunter process.

Titanium

Symbol 

Ti 

Discovered By 

British clergyman and mineralogist William Gregor in 1791

First Isolated by 

Jons Jakob Berzelius in 1825

Named by 

German chemist Martin Heinrich Klaproth 

Atomic number 

22

Standard atomic weight 

47.867

Crystal Structure 

Hexagonal close packed (hcp)

State at 20

Solid 

Melting point 

1668

Boiling point 

3287 ℃ 

Period 

4th 

Group 

4th 

Block 

d

Electronic configuration 

1s2 2s2 2p6 3s2 3p6 3d2 4s2 or [Ar] 3d2 4s2 

Main properties 

Corrosion resistance and highest strength to density ratio 

Main use 

As white pigments and in aircrafts, jet engines, missiles 

Disadvantage 

Titanium powder can cause fire and explosion  

  • Vanadium - Vanadium is one of the most abundant metallic elements and 20th most abundant element in the Earth’s crust. Vanadium has been detected in the light from the Sun and some other stars. Pure vanadium is rare in nature but it's almost 65 various compounds occur naturally. For commercial use vanadium is mostly obtained by extraction of patronite (VS4) ores. It is also found in crude oil, coal, oil shale (Sedimentary rock), tar sands deposits and bauxite ore. It is mostly produced directly from magnetite or heavy oil. It is also obtained as a byproduct of uranium mining. It is produced from steel smelter slag in China and Russia. 

Vanadium 

Symbol 

v

Discovered By 

Spanish Mexican scientist Andres Manuel Del Rio in 1801

First Isolated by 

Swedish Chemist Nils Gabriel Sefstrom in 1830

Named by 

Nils Gabriel Sefstrom

Atomic number 

23

Standard atomic weight 

50.94

Crystal Structure 

Body centered cubic (bcc)

State at 20

Solid 

Melting point 

1910

Boiling point 

3407 ℃ 

Period 

4th 

Group 

5th 

Block 

d

Electronic configuration 

1s2 2s2 2p6 3s2 3p6 3d3 4s2 or [Ar] 3d3 4s2 

Main properties 

Vanadium is good conductor of electricity and insulator to heat

Main use 

As a steel additive 

Disadvantage 

Toxicity 


The F-block Elements or Inner Transition Elements 

F-block includes lanthanoids (4f elements; Ce to Lu) and actinoids (5f elements; Th to Lr). 

The Lanthanoids 

These elements have electronic configuration with 6s2 common but with variable occupancy in 4f – orbitals. 

Properties of Lanthanoids 

  • The lanthanoid contraction – As we move from lanthanum to lutetium, decrease in atomic and ionic radii is observed. This is called lanthanoid contraction. 

  • Elements of lanthanoids series have silvery appearance and have lustre. 

  • All these elements are soft and can be cut by a knife. 

  • Some elements of the series are very reactive while others are less reactive.

  • They have high melting and boiling points. 

  • They react with hydrogen and release energy. 

  • They are strong reducing agents.

  • They react with many nonmetals and form binary compounds. 

  • Lanthanides show high coordination numbers such as 8, 9, 10 or 12 etc. 

  • Chemical reactions of the lanthanoids 

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The Actinoids 

The actinide series includes 14 elements from Thorium to Lawrencium. These elements have electronic configuration with 7s2 common but with variable occupancy in 5f and 6d subshells. 

Properties of Actinoids 

  • All elements of the actinide series are radioactive. 

  • These elements are electropositive. 

  • These metals get spontaneously ignited in the air. 

  • Many allotropes of these elements can be formed. For example, Plutonium has 6 allotropes. 

  • These metals are also soft like lanthanides. 

  • They also react with many nonmetals.

  • Many elements of this series exhibit properties of both d-block and f-block elements. 


Neptunium: An important Element of the Actinoid Series 

Neptunium is the 1st synthetic transuranium metal. Many false claims were made for its discovery. But the 1st time it was originally synthesized by American physicists Edwin McMillan and Philip H. Abelson at Berkeley Radiation Laboratory in 1940. Edwin McMillan got the Nobel prize for synthesizing the transuranium element. They used uranium to synthesize the neptunium element. They prepared a larger sample of bombarded uranium and showed following reaction –

92238U + 01n → 92239Uβ-(23 min)→  93239Npβ- (2.3 days)→  94239Pu

Neptunium is named after the planet Neptune. According to Roman mythology, Neptune is a god of the sea. The word is taken from Latin word Neptunus and Neptune is identified with the Greek god Poseidon. Neptunium is not found in pure elemental form in nature as it is a synthetic element and forms by nuclear reaction of uranium. It generally forms a green coating of its oxide when exposed to moist air. It is a hard, ductile, radioactive and silvery colored actinide metal. 

Neptunium is found in its three allotropic forms – 𝛼 – neptunium, β – neptunium and 𝛾 – neptunium. All three allotropes of neptunium show different symmetry in structure. 𝛼 – neptunium has orthorhombic structure, β – neptunium has tetragonal structure and 𝛾 – Neptunium has a body centered cubic structure. It has almost 24 isotopes. Out of 24 isotopes neptunium -237 is highly stable with half - life of 2.14 x 106 years. Its synthetic isotope neptunium 236 is also very stable with half life of 1.54 x  105 years.


Neptunium 

Symbol 

Np

Discovered By 

American physicists Edwin McMillan and Philip H. Abelson at Berkeley Radiation Laboratory in 1940

Atomic number 

93

Standard atomic weight 

237

Crystal Structure 

Orthorhombic 

State at 20

Solid 

Melting point 

639℃

Boiling point 

4174℃

Period 

7th 

Series 

Actinide 

Block 

f

Electronic configuration 

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 5f4 6d1 7s2 or [Rn] 5f4 6d1 7s2

Main properties 

Paramagnetic, radioactive  

Main use 

In production of plutonium 

Disadvantage 

Toxicity and fire hazards 

This ends our coverage on the topic “The d- and f- Block Elements”. We hope you enjoyed learning and were able to grasp the concepts. You can get separate articles as well on various sub topics such as Uranium, The transition Elements etc. on Vedantu website. We hope after reading this article you will be able to solve problems based on the topic. If you are looking for solutions of NCERT Textbook problems based on this topic, then log on to Vedantu website or download Vedantu Learning App. By doing so, you will be able to access free PDFs of NCERT Solutions as well as Revision notes, Mock Tests and much more.