Writing of electronic configuration of any element is based on three rules as told in previous concepts. They are:
Aufbau principle
Pauli’s exclusion principle
Hund’s rule of maximum multiplicity
The distribution of electrons into orbitals of an atom is called its electronic configuration.
The electronic configuration of the different elements can be represented in two ways:
Subshell notation
Orbital diagram
Let’s understand with the help of examples:
The hydrogen atom has only one electron which goes in the orbital with lowest energy, namely 1s.The E.C of hydrogen is 1s1 (subshell notation)
Orbital diagram:

2. The electronic configuration of lithium is 1s2 2s1. Lithium has 3 electrons as atomic number is 3. 2 electrons filled in 1s orbital and 1 electron filled in 2s orbital.

let us consider fluorine (Z = 9) :
F(Z = 9) = 1s2, 2s2, 2px2, 2py2, 2pz1 or

The importance of knowing the exact electronic configuration of an element lies in the fact that the chemical properties of an element are dependent on the behavior and relative arrangement of its electrons.
| Exam | Chapter |
| JEE MAIN | Atomic Structure |
The electronic configuration of copper is:
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Which law indicates about the pairing of electrons in the same orbital?
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In which of the following pairs, the outer most electronic configuration will be same?
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In the sixth period, the orbitals that are filled are :
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Element "E" belongs to the period 4 and group 16 of the periodic table. The valence shell electron configuration of the element, which is just above "E" in the group is
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The electronic configuration of (atomic number 78) is :
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Number of electrons that Vanadium (Z = 23) has in p-orbitals is equal to ______
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in its ground state electronic configuration has
completely filled orbitals with
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is__________.
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Identify the element for which electronic configuration in oxidation state is
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The element with Z = 120 (not yet discovered) will be an /a :
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The number of unpaired electrons in oxygen atom are
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The number of electrons in penultimate shell of S is
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Total number of electrons in outermost shell of $S e(34)$ is
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In the periodic table, Po belongs to, which group
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The number of electron in outer most shell of Pb
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The number of electrons in the p-subshell of boron is
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The electronic configuration of Indium is-
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The outermost shell's electronic configuration of the elements that occupy the peaks in Lother Meyer's plot of atomic volume versus atomic mass is :
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Which one of the noble gas does not have the electronic configuration of ?
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Which of the following ions is/are diamagnetic in character?
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Consider the ground state of Cr atom . The numbers of electrons with the azimuthal quantum numbers
are, respectively:
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Though nitrogen exhibits +5 oxidation state, it does not form pentahalide. The reason is :
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Given below are two statements one is labeled as Assertion A and the other is labeled as Reason R.
Assertion A: In , isomorphous to
, the metal is present in +1 oxidation state.
Reason R: TI metal has fourteen f electrons in its electronic configuration.
In the light of the above statements, choose the correct answer from the options given below:
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Outermost electronic configuration of a group 13 element, E is . The electronic configuration of an element of p-block period-five placed diagonally to element, E is:
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Which of the following electronic configuration violate Hund's rule for a $p^4$ system of an isolated gaseous species?
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The electronic configuration for Neodymium is :
[Atomic Number for Neodymium 60]
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The number of electrons present in all the completely filled subshells having $\mathrm{n}=4$ and $\mathrm{S}=+\frac{1}{2}$ is___________.
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Choose the correct option having all the elements with $\mathrm{d}^{10}$ electronic configuration from the following :
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Total number of ions from the following the noble gas configuration is ______.
$\mathrm{Sr}^{2+}(\mathrm{z}=38), \mathrm{Cs}^{+}(\mathrm{z}=55), \mathrm{La}^{2+}(\mathrm{z}=57), \mathrm{Pb}^{2+}(\mathrm{z}=82), \mathrm{Yb}^{2+}(\mathrm{z}=70)$ and $\mathrm{Fe}^{2+}(\mathrm{z}=26)$
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Match List I with List II :
| List I (Species) | List II (Electronic distribution) | ||
| A. | $\mathrm{Cr}^{+2}$ | I. | $3 \mathrm{~d}^8$ |
| B. | $\mathrm{Mn}^{+}$ | II. | $3 \mathrm{~d}^3 4 \mathrm{~s}^1$ |
| C. | $\mathrm{Ni}^{+2}$ | III. | $3 \mathrm{~d}^4$ |
| D. | $\mathrm{V}+$ | IV. | $3 \mathrm{~d}^5 4 \mathrm{~s}^1$ |
Choose the correct answer from the options given below :
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The lowest oxidation number of an atom in a compound $\mathrm{A}_2 \mathrm{~B}$ is -2 . The number of electrons in its valence shell is________.
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The correct Slater electronic configuration
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In the transition elements, the incoming electron occupies (n-1)d sublevel in preference to:
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If the electronic configuration of an element is $1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^2 4 s^2$, the four electrons involved in chemical bond formation will be_____.
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In which of the following pairs, the ions are iso-electronic?
(i) $N a^{+}, \mathrm{Mg}^{2+}$
(ii) $\mathrm{Al}^{3+}, \mathrm{O}^{-}$
(iii) $\mathrm{Na}^{+}, \mathrm{O}^{2-}$
(iv) $\mathrm{N}^{3-}, \mathrm{Cl}^{-}$
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The electronic configurations of three elements A, B and C are given below.
Answer the questions from 14 to 17 on the basis of these configurations.
$\begin{aligned} & \text { A } 1 s^2 2 s^2 2 p^6 \\ & \text { B } 1 s^2 2 s^2 2 p^6 3 s^2 3 p^3 \\ & \text { C } 1 s^2 2 s^2 2 p^6 3 s^2 3 p^5\end{aligned}$
The bond between B and C will be
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How many unpaired electrons are present in ground state electronic configuration of silicon atom?
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How many unpaired electrons are present in ground state electronic configuration of Te(Z=52)
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The incorrect electron configuration of a noble gas
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No. of electron in 3d subshell and 4s subshell in Cu respectively are
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No. of electrons in 3d subshell and total No. of electrons in "Cr" respectively.
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The last element of the p-block in 6th period is represented by the outermost electronic configuration:
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Among the following the set of isoelectronic ions is
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If an extra electron is added to the hypothetical molecule $C_2$, this extra electron will occupy the molecular orbital:
(A) $\Pi_{2 p}$ *
$(B) \Pi_{2 p}$
$(C) \sigma_{2 p^*}$
$(D) \sigma_{2 p}$
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Which one of the following species responds to an external magnetic field?
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How many electrons are present in 2p subshell of Na atom?
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How many unpaired electrons are there in the electroinc configuration of Potassium atom?
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The metal ion with total number of electrons same as $S^{2-}$ is:
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The number of valence electrons in an atom with electronic configuration $1 s^2 2 s^2 2 p^6 3 s^2 3 p^3$ is:
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Niobium (Nb) and ruthenium (Ru) have “x” and “y” number of electrons in their respective 4d
orbitals. The value of x + y is _______
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Identify the orbital of the excited electron in the atom with an electronic configuration of [Xe] 6s2 4f14 5d9 6p1
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The electronic configurations of three elements A, B and C are given below. Answer the questions from 14 to 17 on the basis of these configurations.
A $1 s^2 2 s^2 2 p^6$
B $1 s^2 2 s^2 2 p^6 3 s^2 3 p^3$
C $1 s^2 2 s^2 2 p^6 3 s^2 3 p^5$
The molecular formula of the compound formed from B and C will be
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The electronic configurations of three elements A, B and C are given below. Answer the questions from 14 to 17 on the basis of these configurations.
$\begin{aligned} & \text { A } 1 s^2 2 s^2 2 p^6 \\ & \text { } 1 s^2 2 s^2 2 p^6 3 s^2 3 p^3 \\ & \text { } 1 s^2 2 s^2 2 p^6 3 s^2 3 p^5\end{aligned}$
Stable form of A may be represented by the formula
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The order of screening effect of electrons of s, p, d and f orbitals of a given shell of an atom on its outer shell electrons is:
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The pair of ions having same electronic configuration is............
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Match List I with List II
| List-I (Element) |
List-II (Electronic Configuration) |
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| A | N | I. | $[\mathrm{Ar}] 3 \mathrm{~d}^{10} 4 \mathrm{~s}^2 4 \mathrm{p}^5$ |
| B | S | II. | $[\mathrm{Ne}] 3 \mathrm{~s}^2 3 \mathrm{p}^4$ |
| C | Br. | III. | $[\mathrm{He}] 2 \mathrm{~s}^2 2 \mathrm{p}^3$ |
| D | Kr. | IV. | $[\mathrm{Ar}] 3 \mathrm{~d}^{10} 4 \mathrm{~s}^2 4 \mathrm{p}^6$ |
Choose the correct answer from the options given below :
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Total number of unpaired electrons present in $\mathrm{Co}^{3+}$ (Atomic number $=27$ ) is
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Total number of unpaired electrons present in $C r^{3+}$ (Atomic number $=24$ ) is
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Total number of unpaired electrons present in $\mathrm{Mn}^{2+}$ (Atomic number $=25$ ) is
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The electronic configuration of $\mathrm{Cu}(\mathrm{II})$ is $3 \mathrm{~d}^9$ whereas that of $\mathrm{Cu}(\mathrm{I})$ is $3 \mathrm{~d}^{10}$. Which of the following is correct?
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The electronic configuration of an element is $1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^5 4 s^1$ This represents its:
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The total number of species from the following in which one unpaired electron is present, is _______.
$\mathrm{N}_2, \mathrm{O}_2, \mathrm{C}_2^{-}, \mathrm{O}_2^{-}, \mathrm{O}_2^{2-}, \mathrm{H}_2^{+}, \mathrm{CN}^{-}, \mathrm{He}_2^{+}$
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The electronic configuration of Einsteinium is:
(Given atomic number of Einsteinium $=99$ )
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Which of the following is electronic configration of Li?
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Which of the following options does not represent ground state electronic configuration of an atom?
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The distribution of electrons into orbitals of an atom is called its electronic configuration. If one keeps in mind the basic rules which govern the filling of different atomic orbitals, the electronic configurations of different atoms can be written very easily.