Electronic Configuration of First 30 Elements

Electronic configuration describes the distribution of electrons in atomic orbits. It tells about how electrons are arranged in the orbits inside the atom. Knowing any element's electronic configuration helps us to find its physical and chemical properties.

In this article, we will learn how to write electronic configuration of elements, Electronic configuration of the first 30 elements, and the significance of electric configuration.

What is Electronic Configuration?

Electric Configuration is the arrangement of electrons within the energy levels, sublevels, and orbitals of its atoms. It describes the distribution of electrons in different shells (energy levels) and subshells (s, p, d, f) according to the rules of quantum mechanics.

Representation of electrons distributed in atomic shells of an element is known as electronic configuration. The electrons are mathematically located in these subshells and the notations help locate the position of these electrons and the electronic configuration. 

How to Write Electronic Configuration of Elements?

To write the Electronic Configuration of an element, we must know the properties of that particular element, such as its atomic number, number of electrons, shells, etc. We must follow the following rules to write the electronic configuration of any element.

Rules for Filling Electrons in Orbitals

The maximum number of electrons that can be accommodated in a shell is dependent on the principal quantum number (n).

The maximum number of electrons in any shell is 2n² , where n is the shell number.

• For K shell, n=1 and maximum electrons present in k shell = 2 × (1)² = 2.
• For L shell, n=2 and maximum electrons present in L shell = 2 × (2)² = 8.
• For M shell, n=3 and maximum electrons present in M shell = 2 × (3)² = 18.
• For N shell, n=4 and maximum electrons present in N shell = 2 × (4)² = 32.

The number of electrons in subshells are dependent on the azimuthal quantum number(L). The value of L is in between 0 to (n-1) where n is principal quantum number.

For each value of L , there is corresponding subshell

• L = 0 corresponds to s subshell,
• L = 1 corresponds to p subshell,
• L = 2 corresponds to d subshell and
• L = 3 corresponds to f subshell.

Similar to principal quantum number we can also calculate maximum number of electrons present in each subshell using L .

The maximum number of electrons that can be present in subshell = 2 × (2L+1) .

Hence, the maximum number of electrons in each subshell are:

• In S subshell = 2 × (2(0)+1) = 2
• In P sub shell = 2 × (2(1)+1) = 6,
• In D subshell = 2 × (2(2)+1) = 10 and
• In F subshell = 2 × (2(3)+1) = 14.

Note: While writing electronic configuration of any element first shell number is written followed by subshell name and then total number of electrons in the subshell with superscript.

For example , if 1 electron is present in first subshell then its electronic configuration is 1s¹ .

Aufbau Principle

Aufbau principle states that electrons are filled in the increasing order of orbital energy level. The atomic orbitals with lower energy are filled first and then the orbital with higher energy is filled.

Pauli Exclusion Principle

Pauli Exclusion Principle states that no two electrons in an atom can have identical values for all four of their quantum numbers. In this principle, it states that no more than two electrons can occupy the same orbital and two electrons in same orbital must have opposite spins.

General Electronic Configuration of Elements

The general electronic configuration of elements according to their respective blocks is given below:

• s-block : ns^1-2
• p-block : ns²np^1-6
• d-block : (n-1)d^1-10ns^0-2
• f-block : (n-2)f^1-14(n-1)d^0-1ns²

s and p bock elements are called representative elements, d block elements are called transition elements and f-block elements are called inner transition elements.

Electronic Configuration of First 30 elements

Electric Configuration of first 30 elements is given below:

Atomic Number	Element	Element Symbol	Electronic Configuration
1	Hydrogen	H	1s1
2	Helium	He	1s2
3	Lithium	Li	[He] 2s1
4	Beryllium	Be	[He] 2s2
5	Boron	B	[He] 2s2 2p1
6	Carbon	C	[He] 2s2 2p2
7	Nitrogen	N	[He] 2s2 2p3
8	Oxygen	O	[He] 2s2 2p4
9	Fluorine	F	[He] 2s2 2p5
10	Neon	Ne	[He] 2s2 2p6
11	Sodium	Na	[Ne] 3s1
12	Magnesium	Mg	[Ne] 3s2
13	Aluminum	Al	[Ne] 3s2 3p1
14	Silicon	S	[Ne] 3s2 3p2
15	Phosphorus	P	[Ne] 3s2 3p3
16	Sulphur	S	[Ne] 3s2 3p4
17	Chlorine	Cl	[Ne] 3s2 3p5
18	Argon	Ar	[Ne] 3s2 3p6
19	Potassium	K	[Ar] 4s1
20	Calcium	Ca	[Ar] 4s2
21	Scandium	Sc	[Ar] 3d1 4s2
22	Titanium	Ti	[Ar] 3d2 4s2
23	Vanadium	V	[Ar] 3d3 4s2
24	Chromium	Cr	[Ar] 3d5 4s1
25	Manganese	Mn	[Ar] 3d5 4s2
26	Iron	Fe	[Ar] 3d6 4s2
27	Cobalt	Co	[Ar] 3d7 4s2
28	Nickel	Ni	[Ar] 3d8 4s2
29	Copper	Cu	[Ar] 3d10 4s1
30	Zinc	Zn	[Ar] 3d10 4s2

Electronic Configuration of First 10 Elements

The electronic configurations of the first 10 elements are as follows:

Atomic Number	Element	Electronic Configuration
1	Hydrogen (H)	1s1
2	Helium (He)	1s2
3	Lithium (Li)	1s2 2s1
4	Beryllium (Be)	1s2 2s2
5	Boron (B)	1s2 2s2 2p1
6	Carbon (C)	1s2 2s2 2p2
7	Nitrogen (N)	1s2 2s2 2p3
8	Oxygen (O)	1s2 2s2 2p4
9	Fluorine (F)	1s2 2s2 2p5
10	Neon (Ne)	1s2 2s2 2p6

Electronic Configuration of Elements 11 to 20

The electronic configurations of the elements 11 to 20 are as follows:

Atomic Number	Element	Electronic Configuration
11	Sodium (Na)	1s2 2s2 2p6 3s1
12	Magnesium (Mg)	1s2 2s2 2p6 3s2
13	Aluminum (Al)	1s2 2s2 2p6 3s2 3p1
14	Silicon (Si)	1s2 2s2 2p6 3s1 3p2
15	Phosphorus (P)	1s2 2s2 2p6 3s1 3p3
16	Sulfur (S)	1s2 2s2 2p6 3s1 3p4
17	Chlorine (Cl)	1s2 2s2 2p6 3s1 3p5
18	Argon (Ar)	1s2 2s2 2p6 3s1 3p6
19	Potassium (K)	1s2 2s2 2p6 3s1 3p6 4s1
20	Calcium (Ca)	1s2 2s2 2p6 3s1 3p6 4s2

Electronic Configuration of Elements 21 to 30

The electronic configurations of the elements 21 to 30 are as follows:

Atomic Number	Element	Electronic Configuration
21	Scandium (Sc)	1s2 2s2 2p6 3s1 3p6 4s2 3d1
22	Titanium (Ti)	1s2 2s2 2p6 3s1 3p6 4s2 3d2
23	Vanadium (V)	1s2 2s2 2p6 3s1 3p6 4s2 3d3
24	Chromium (Cr)	1s2 2s2 2p6 3s1 3p6 4s1 3d5
25	Manganese (Mn)	1s2 2s2 2p6 3s1 3p6 4s2 3d5
26	Iron (Fe)	1s2 2s2 2p6 3s1 3p6 4s2 3d6
27	Cobalt (Co)	1s2 2s2 2p6 3s1 3p6 4s2 3d7
28	Nickel (Ni)	1s2 2s2 2p6 3s1 3p6 4s2 3d8
29	Copper (Cu)	1s2 2s2 2p6 3s1 3p6 4s1 3d10
30	Zinc (Zn)	1s2 2s2 2p6 3s1 3p6 4s2 3d10

Significance of Electronic Configuration

The importance of electronic configuration is described below:

• It helps in determining valency of element which is useful in finding chemical behavior of element.

• The elements are classified in different blocks from electronic configuration (S-block, P-block , D-block and F-block elements).

• Electronic configuration helps in determining atomic spectra of element.

• Electronic configuration influences the magnetic properties of elements.

• Electronic configuration of an element is used to determine different periodic trends of the periodic table, such as atomic size, ionization energy, and electron affinity.

Read More,

• Electronic configuration
• Electronic Configuration of d-block elements.
• Arrangement of Electrons in an atom

Solved Examples on Electronic Configuration

Example 1: What is the electronic configuration of magnesium?

Solution:

Atomic number of magnesium is 12. Hence its electronic configuration is 1s²2s²2p⁶3s².

Example 2: What is the maximum number of electrons present in shell with principal quantum number of 4?

Solution:

Maximum number of electrons in shell with principle quantum number 4 is = 2×(4)² = 32.

Example 3: What is the maximum number of electrons present in subshell with L=2 ?

Solution:

Maximum number of electrons in subshell with L = 2 is = 2(2(2)+1) = 10.

Example 4: Which of the following elements shown as pairs with their atomic numbers belong to the same period ?

• a. Z=19 and Z=38
• b. Z=12 and Z=17
• c. Z=11 and Z=21
• d. Z=16 and Z=35

Solution:

b. Z=12 and Z=17

For Z=12 electronic configuration is = 1s2s²2p²3s²

For Z=17 electronic configuration is = 1s²2s²2p⁶3s²3p⁵

Both of elements have n=3. hence they belong to same period.

Example 5:Atomic numbers of few elements are given below. Which of the pairs belong to s-block ?

• a. 7,14
• b. 3,20
• c. 8,15
• d. 9,17

Solution:

b. 3,20

Electronic configuration for Z=3 , 1s²2s¹ and for Z=20 , 1s²2s²2p⁶3s²3p⁶4s²

Hence they belong to s block.