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Electronic Configurations of D Block Elements

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D Block Elements or Transition Elements Electronic Configurations

Groups 3 to 12 elements are called d-block or transition elements. These elements are present between p-block and s-block elements in the periodic table. These elements’ properties are intermediate between the properties of s -block and p -block elements, i.e. d -block elements represent a change or transition in properties from most electropositive s - block elements to less electropositive p - block elements. Therefore, these elements are called transition elements.


The d-block elements include the most common metals used in construction and manufacturing, metals that are valued for their beauty (gold, silver and platinum), metals used in coins (nickel, copper) and metals used in modern technology (titanium). 

In the transition element, the last differentiating electron is accommodated on penultimate d-orbitals, i.e., d-orbitals are successively filled. The general electronic configuration of transition elements is:


(n-1)1-10 ns 0,1 or 2


There are four complete rows (called series) of ten elements each corresponding to filling of 3d, 4d, 5d and 6d-orbitals respectively. Each series starts with a member of group third (IIIB) and ends with a member of group twelve (IIB).

Why are D-block elements also referred to as Transition elements (In Brief)?

Groups 4-11 are made up of transition components. Transition elements include scandium and yttrium from Group 3, which have a partly filled d subshell in the metallic form. Elements in the 12 columns of the d block, such as Zn, Cd, and Hg, have entirely filled d-orbitals and are hence not considered transition elements.


Transition Elements get their name from the fact that they are placed between s and p block elements and have characteristics that transition between them. So, while all transition metals are d block elements, they are not all transition elements. Filling Transition Metal Orbitals

The first-row transition metal electron configuration consists of 4s and 3d subshells with a core of argon (noble gas). This applies only to transition metals in the first row, adjustments are required when writing the electron configuration for the other transition metal rows. Before the first row of transition metals, the noble gas would be the core written around the element symbol with brackets (i.e. Ar-Ar would be used for the first row of transition metals), and the electron configuration would follow an Ar-Ar nsxndx format. The electron configuration for first-row transition metals would simply be Ar-Ar 4sx3dx. Based on the periodic table, the energy level, "n," can be determined simply by looking at the row number in which the element is located. There is, however, an exception for the d-block and f-block, where the energy level, "n" for the d-block is "n-1" ("n" minus 1) and "n-2" for the f-block (see the following periodic classification table). The "x" in nsx and ndx, in this case, is the number of electrons in a particular orbital (i.e. s - orbitals can hold up to 2 electrons, p - orbitals can hold up to 6 electrons, d - orbitals can hold up to 10 electrons, and f - orbitals can hold up to 14 electrons). To determine what "x" is, simply count the number of boxes you will find before you reach the element you are trying to determine the configuration of the electron.

First transition or 3d-series: 

Elements: Sc(21) to Zn(30). 3d-orbitals are gradually filled up.


Element

Symbol

At. No.

Electronic Configuration

Scandium

Sc

21

Ar-Ar 3d142

Titanium

Ti

22

Ar-Ar 3d242

Vanadium

V

23

Ar

Ar 3d342

Chromium

Cr

24

Ar-Ar 3d541

Manganese

Mn

25

Ar-Ar 3d542

Iron

Fe

26

Ar-Ar 3d642

Cobalt

Co

27

Ar-Ar 3d742

Nickel

Ni

28

Ar-Ar 3d842

Copper

Cu

29

Ar-Ar 3d1041

Zinc

Zn

30

Ar-Ar 3d1042

 

The actual configurations are explained on the basis of the stability concept of half-filled or completely filled (n-l) d-orbitals. (n-l) d-subshell is more stable when 5 or 10 electrons are present, i.e., every d-orbital is either singly occupied or doubly occupied.

Second Transition or 4d-series

This series consists of elements from Y(39) to Cd(48). 4d-orbitals are gradually filled up.

Element

Symbol

At. No.

Electronic Configuration

Yttrium

Y

39

Kr

Kr 4d1 5s2

Zirconium

Zr

40

Kr

Kr 4d2 5s2

Niobium

Nb

41

Kr

Kr 4d4 5s1

Molybdenum 

Mo

42

Kr

Kr 4d5 5s1

Technetium

Tc

43

Kr

Kr 4d6 5s2

Ruthenium

Ru

44

Kr

Kr 4d7 5s2

Rhodium

Rh

45

Kr

Kr 4d8 5s1

Palladium

Pd

46

Kr

Kr 4d10 5s0

Silver

Ag

47

Kr

Kr 4d10 5s1

Cadmium

Cd

48

Kr

Kr 4d10 5s2

 

Elements marked with an asterisk have anomalous configurations. Nuclear-electron and electron-electron forces are attributed factors.

Third Transition or 5d-series: 

This series consists of elements from La(S7) to Hg(80) except 14 elements of lanthanide series from Ce(S8) to Lu(71). 5d-orbitals are gradually filled up.

 

Element

Symbol

At. No.

Electronic Configuration

Lanthanum 

La

57

Xe

Xe 5d1 6s2

Hafnium

Hf

72

Xe

Xe 4f14 5d2 6s2

Tantalum

Ta

73

Xe

Xe 4f14 5d3 6s2

Tungsten

W

74

Xe

Xe 4f14 5d4 6s2

Rhenium

Re

75

Xe

Xe 4f14 5d5 6s2

Osmium

Os

76

Xe

Xe 4f14 5d6 6s2

Iridium

Ir

77

Xe

Xe 4f14 5d7 6s2

Platinum

Pt

78

Xe

Xe 4f14 5d8 6s1

Gold

Au

79

Xe

Xe 4f14 5d9 6s1

Mercury

Hg

80

Xe

Xe 4f14 5d10 6s2



Fourth Transition or 6d-series 

This series consists of elements from Ac(89) to Uub(112) except 14 elements of the actinide series from Th(90) to Lr(103). 6d-orbitals are gradually filled up.

 

Element

Symbol

At. No.

Electronic configuration

Actinium

Ac

89

Rn

Rn 6d1 7s2

Rutherfordium

Rf

104

Rn

Rn 5f14 6d2 7s2

Hahnium

Ha

105

Rn

Rn 5f14 6d3 7s2

Seaborgium

Sg

106

Rn

Rn 5f14 6d4 7s2

Bohrium

Bh

107

Rn

Rn 5f14 6d5 7s2

Hassium

Hs

108

Rn

Rn 5f14 6d6 7s2

Meitnerium

Mt

109

Rn

Rn 5f14 6d7 7s2

Ununnilium (Darmstadtium) 

Uun

110

Rn

Rn 5f14 6d8 7s2

Unununium (Rontgenium)

Uuu

111

Rn

Rn 5f14 6d10 7s1

Ununbium

Uub

112

Rn

Rn 5f14 6d10 7s1

Variable Oxidation State of D-block Elements 

The oxidation state is a notional condition in which the atom seems to lose or gain more electrons than it does in its normal valency state. It's still useful for understanding the atom's characteristics.  Both s and d-orbitals can have electrons in transition elements.


Because the energy difference between the s and d orbitals is modest, both electrons can participate in the production of ionic and covalent bonds, resulting in multiple(variable) valency states (oxidation states).


As a result, any transition element can have a minimum oxidation state equal to the number of s-electrons and a maximum oxidation state equal to the total number of electrons in both s and d-orbitals. Between oxidation states, new oxidation states become feasible.


JEE Main Chemistry Chapter-wise Solutions 2023-24 

 

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FAQs on Electronic Configurations of D Block Elements

1. What is the electronic configuration of D-Block Elements?

The electrical configuration of D block elements is (n-1)d 1-10ns 1-2. Half-filled orbitals and filled d orbitals are both stable for these elements. The electronic configuration of chromium, which includes half-filled d and s orbitals in its configuration – 3d54s1, is an example of this. Another example is the electrical configuration of copper. Copper has a 3d104s1 electronic setup rather than a 3d94s2. According to the Aufbau principle and Hund's rule of multiplicity, electrons are added to the 3d subshell from left to right along the period.

2. Why do elements in d-block have a varying range of oxidation states?

The large variety of oxidation states (oxidation numbers) that transition metals may exhibit is one of their most notable characteristics. Because the 4s and 3d sublevels are so near in energy, variable oxidation states are feasible. Either of these sublevels is quite easy to lose electrons from.


However, to say that only transition metals may have different oxidation states is incorrect. Sulphur, nitrogen, and chlorine, for example, have a very wide variety of oxidation states in their compounds and are not transition metals.

3. From where students can access detailed information about d-block elements?

Vedantu is the right place for all of your queries and provides you best solution regarding your search for d-block elements. The experts have explained the topic in a very detailed and organised manner. It will help students in preparing for their respective competitive exams and enable students to get fluent with in-organic chemistry. D-block elements are one of the most important topics in Class 11 and 12 Chemistry. Vedantu’s advantage can help students to learn and understand the topic in-depth with ease and comfort.

4. What makes transition metals colourful?

Partially filled (n-1)d orbitals are associated with a coloured transition element compound. Unpaired d-electrons in transition metal ions undergo the electronic transition from one d-orbital to another. During the d-d transition, electrons absorb a portion of the radiation's energy and release the rest as coloured light. The colour of an ion is the opposite of the colour it absorbs. As a result, coloured ions are generated as a result of the d-d transition, which is evident for all transition elements.

5. Does d-block contain any non-metallic element?

All of the elements in the d-block are metals, and the majority of them have one or more chemically active d-orbital electrons. The number of electrons engaging in chemical bonding might vary due to the minor variation in energy between the different d-orbital electrons. The elements in the d-block tend to have two or more oxidation states that differ by multiples of one. +2 and +3 are the most prevalent oxidation states. Chromium, iron, molybdenum, ruthenium, tungsten, and osmium have oxidation numbers as low as 4, whereas iridium has the unique ability to achieve an oxidation state of +9.