Ground state electron configuration / Atomic structure and particle

Periodic property of elements is the Chemical properties of elements depends upon the ground state electron configuration (GSEC) of that elements.

So to understand and predict the properties of elements, it is inevitable to understand the (GSEC) of an atom or elements.

Understanding ground state Electron configuration

GSEC is a systematic distribution of electrons in atomic orbits of an atom or element. It has immense importance in knowing valency of an atom or molecules in chemical reactions.

Many scientists worked to give exact electron configuration in of specific atoms. They proposed models and principles to predict and provide such configuration in atoms.

Ground state energy orbit

Ground state energy orbit is low energy orbit in which electron prefers to enter first in the process of electron configuration. For example, “S” orbital of 4th orbit having less energy compared to “P” orbital of 3rd orbit. So, 4s orbitalis in a ground energy state.

Presentation of electron arrangement

Electron arrangement in an atom is presented by two methods. One is orbital method as box method suggested by Pauli and another is electron configuration notation.

In orbital diagram method electrons are arranged in boxes with vertical upward and downward arrows indicating spin of electrons.

In electron configuration notation method, electrons are shown in their principle quantum numbers and atomic orbital sub-levels. For example electron configuration notation for Sodium (Na) is as follows
1s² 2s² 2p⁶ 3s²

Noble gas configuration

Electron configuration notion for elements of higher number of electrons becomes cumbersome. To avoid this, a method of noble gas configuration does the work. Symbols of noble gas elements shown in bracket and after that remaining notation is written as it is.

Ground state electron configuration

Electron configuration of Chromium : Cr 29

1s^2
2s^2 2p^6
3s^2 3p^6
4s^1 3d^5

Or simply

[Ar] 4s^1 3d^5

Electron configuration of Silver: Ag 47

1s^2
2s^2 2p^6
3s^2 3p^6
4s^2 3d^10 4p^6
5s^1 4d^10

Or simply

[Kr] 5s^1 4d^10

Electron configuration of Uranium : Ur 92

1s^2
2s^2 2p^6
3s^2 3p^6
4s^2. 3d^10 4p^6
5s^2 4d^10 5p^6
6s^2 4f^14 5d^10 6p^6
7s^2 5f^3 6d^1

Or simply

[Rn] 7s^2 5f^3 6d^1

Short Summary of topic

Chemical properties of elements depend upon the GSEC of that elements.

Ground state electron configuration is a systematic distribution of electrons in atomic orbits of an atom or element.

It is essential to know the valency of an atom or molecules in chemical reactions.

Ground state energy orbit is low energy orbit in which electron prefers to enter first in the process of electron configuration.

In orbital diagram method electrons are arranged in boxes with vertical upward and downward arrows indicating spin of electrons.

Method of noble gas configuration does the Work Of Electron configuration notion for elements of higher number of electrons.

Solved Questions for practice

Here are some useful solved questions on the given topic for better practice. Just take a look at the following solved questions.

Q.1. What is ground state electron configuration?

Ans: It is a systematic distribution of electrons in atomic orbits of an atom or element. It helps to understand the valency of an atom or molecules in chemical reactions.