Cadmium electron configuration

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The cadmium electron configuration, denoted as [Kr] 5s² 4d¹⁰ or 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰, showcases the specific placement of electrons within the atom. This configuration can be determined through various methods, including the aufbau principle, periodic table organization, Bohr model representation, or orbital diagram visualization.

Contents

Methods

Aufbau principle

First, find electrons of cadmium atom

The atomic number of cadmium represents the total number of electrons of cadmium. Since the atomic number of cadmium is 48, the total electrons of cadmium are 48.

Second, make a table of subshell and its maximum electrons

Calculate the maximum number of electrons each subshell can hold using the formula: 4ℓ + 2

Where, ℓ = azimuthal quantum number of the subshell

For s subshell, ℓ = 0
For p subshell, ℓ = 1
For d subshell, ℓ = 2
For f subshell, ℓ = 3

subshell	max. electrons
s	2
p	6
d	10
f	14

This means that,

Each s subshell can hold maximum 2 electrons
Each p subshell can hold maximum 6 electrons
Each d subshell can hold maximum 10 electrons
Each f subshell can hold maximum 14 electrons

Finally, use aufbau chart and start writing electron configuration

Remember that we have a total of 48 electrons.

According to the aufbau principle, 1s subshell is filled first and then 2s, 2p, 3s… and so on.

Use 2 electrons for 1s subshell | Image: Learnool

By looking at the chart, you can see that electrons are first filled in 1s subshell. Each s-subshell can hold a maximum of 2 electrons, so we will use 2 electrons for the 1s subshell.

So the electron configuration will be 1s². Where, 1s² indicates that the 1s subshell has 2 electrons.

Now we have used 2 electrons in the 1s subshell, so we have a total of 48 – 2 = 46 electrons left.

Use 2 electrons for 2s subshell | Image: Learnool

Looking at the chart, after 1s subshell now comes 2s subshell. Again, each s-subshell can hold a maximum of 2 electrons, so we will use 2 electrons for the 2s subshell.

So the electron configuration will be 1s² 2s². Where, 2s² indicates that the 2s subshell has 2 electrons.

Again, we have used 2 electrons in the 2s subshell, so we have a total of 46 – 2 = 44 electrons left.

Use 6 electrons for 2p subshell | Image: Learnool

After 2s subshell now comes 2p subshell. Each p-subshell can hold a maximum of 6 electrons, so we will use 6 electrons for the 2p subshell.

So the electron configuration will be 1s² 2s² 2p⁶. Where, 2p⁶ indicates that the 2p subshell has 6 electrons.

Here, we have used 6 electrons in the 2p subshell, so we have a total of 44 – 6 = 38 electrons left.

Use 2 electrons for 3s subshell | Image: Learnool

After 2p subshell now comes 3s subshell. Each s-subshell can hold a maximum of 2 electrons, so we will use 2 electrons for the 3s subshell.

So the electron configuration will be 1s² 2s² 2p⁶ 3s². Where, 3s² indicates that the 3s subshell has 2 electrons.

Here, we have used 2 electrons in the 3s subshell, so we have a total of 38 – 2 = 36 electrons left.

Use 6 electrons for 3p subshell | Image: Learnool

After 3s subshell now comes 3p subshell. Each p-subshell can hold a maximum of 6 electrons, so we will use 6 electrons for the 3p subshell.

So the electron configuration will be 1s² 2s² 2p⁶ 3s² 3p⁶. Where, 3p⁶ indicates that the 3p subshell has 6 electrons.

Here, we have used 6 electrons in the 3p subshell, so we have a total of 36 – 6 = 30 electrons left.

Use 2 electrons for 4s subshell | Image: Learnool

After 3p subshell now comes 4s subshell. Each s-subshell can hold a maximum of 2 electrons, so we will use 2 electrons for the 4s subshell.

So the electron configuration will be 1s² 2s² 2p⁶ 3s² 3p⁶ 4s². Where, 4s² indicates that the 4s subshell has 2 electrons.

Here, we have used 2 electrons in the 4s subshell, so we have a total of 30 – 2 = 28 electrons left.

Use 10 electrons for 3d subshell | Image: Learnool

After 4s subshell now comes 3d subshell. Each d-subshell can hold a maximum of 10 electrons, so we will use 10 electrons for the 3d subshell.

So the electron configuration will be 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰. Where, 3d¹⁰ indicates that the 3d subshell has 10 electrons.

Here, we have used 10 electrons in the 3d subshell, so we have a total of 28 – 10 = 18 electrons left.

Use 6 electrons for 4p subshell | Image: Learnool

After 3d subshell now comes 4p subshell. Each p-subshell can hold a maximum of 6 electrons, so we will use 6 electrons for the 4p subshell.

So the electron configuration will be 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶. Where, 4p⁶ indicates that the 4p subshell has 6 electrons.

Here, we have used 6 electrons in the 4p subshell, so we have a total of 18 – 6 = 12 electrons left.

Use 2 electrons for 5s subshell | Image: Learnool

After 4p subshell now comes 5s subshell. Each s-subshell can hold a maximum of 2 electrons, so we will use 2 electrons for the 5s subshell.

So the electron configuration will be 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s². Where, 5s² indicates that the 5s subshell has 2 electrons.

Here, we have used 2 electrons in the 5s subshell, so we have a total of 12 – 2 = 10 electrons left.

Use last 10 electrons for 4d subshell | Image: Learnool

After 5s subshell now comes 4d subshell. Each d-subshell can hold a maximum of 10 electrons, and we also have 10 electrons left, so we will use that 10 electrons for the 4d subshell.

So the electron configuration will be 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰. Where, 4d¹⁰ indicates that the 4d subshell has 10 electrons.

Therefore, the final electron configuration of cadmium is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰. And the condensed/abbreviated electron configuration of cadmium is [Kr] 5s² 4d¹⁰.

Where, Kr is krypton

Periodic table

First, get periodic table chart with spdf notation

The above image shows periodic table blocks.

The ‘s’ in s block represents that all s block elements have their valence electrons in s subshell. Similarly, the ‘p’ in p block represents that all p block elements have their valence electrons in p subshell. And so on for d block and f block.

Second, mark location of cadmium on periodic table

Cadmium is the d block element located in group 12 and period 5. Hence, mark the location of cadmium on the periodic table as follows:

Mark location of cadmium on periodic table | Image: Learnool

Finally, start writing electron configuration

Remember that: each s subshell can hold maximum 2 electrons, each p subshell can hold maximum 6 electrons, each d subshell can hold maximum 10 electrons, and each f subshell can hold maximum 14 electrons.

Start writing electron configuration from the very first element (i.e., hydrogen) all the way up to cadmium.

Start from 1s and write till Cd for full electron configuration | Image: Learnool

So the electron configuration of cadmium will be 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰.

Bohr model

In the above image, 1 represents the 1^st electron shell. Similarly, 2 represents the 2^nd electron shell, 3 represents the 3^rd electron shell, 4 represents the 4^th electron shell, and 5 represents the 5^th electron shell.

The 1^st electron shell contains 1s subshell, the 2^nd electron shell contains 2s and 2p subshells, the 3^rd electron shell contains 3s, 3p, and 3d subshells, the 4^th electron shell contains 4s, 4p, and 4d subshells, and the 5^th electron shell contains 5s subshell.

We know that each s subshell can hold maximum 2 electrons, each p subshell can hold maximum 6 electrons, each d subshell can hold maximum 10 electrons, and each f subshell can hold maximum 14 electrons.

Also, we have to make sure that the electron configuration will match the order of aufbau principle (i.e., the 1s subshell is filled first and then 2s, 2p, 3s… and so on).

So the electron configuration of cadmium will be 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰.

Where,

1s² indicates that the 1s subshell has 2 electrons
2s² indicates that the 2s subshell has 2 electrons
2p⁶ indicates that the 2p subshell has 6 electrons
3s² indicates that the 3s subshell has 2 electrons
3p⁶ indicates that the 3p subshell has 6 electrons
4s² indicates that the 4s subshell has 2 electrons
3d¹⁰ indicates that the 3d subshell has 10 electrons
4p⁶ indicates that the 4p subshell has 6 electrons
5s² indicates that the 5s subshell has 2 electrons
4d¹⁰ indicates that the 4d subshell has 10 electrons

Learn how to draw: Cadmium Bohr model

Orbital diagram

The above orbital diagram shows that the 1s subshell has 2 electrons, the 2s subshell has 2 electrons, the 2p subshell has 6 electrons, the 3s subshell has 2 electrons, the 3p subshell has 6 electrons, the 4s subshell has 2 electrons, the 3d subshell has 10 electrons, the 4p subshell has 6 electrons, the 5s subshell has 2 electrons, and the 4d subshell has 10 electrons.

So the electron configuration of strontium will be 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰.

Next: Hafnium electron configuration

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Learnool.com was founded by Deep Rana, who is a mechanical engineer by profession and a blogger by passion. He has a good conceptual knowledge on different educational topics and he provides the same on this website. He loves to learn something new everyday and believes that the best utilization of free time is developing a new skill.