# Potassium Bohr model

In the potassium Bohr model, the nucleus contains 19 protons and 20 neutrons. Around this nucleus are four electron shells, containing a total of 19 electrons.

To draw the potassium Bohr model, outline the 19 protons, 20 neutrons, and 19 electrons. Begin by illustrating the nucleus, and then depict the four electron shells. The first three shells should contain 2, 8, and 8 electrons, respectively, while the fourth shell holds the remaining electron.

Contents

## Steps

### Write protons, neutrons, and electrons of potassium atom

Potassium has 19 protons, 20 neutrons, and 19 electrons.

### Draw nucleus of potassium atom

The nucleus of a potassium atom contains 19 protons and 20 neutrons. So draw the nucleus of potassium atom as follows:

Now in the next step, draw the 1st electron shell and start marking electrons.

### Draw 1st electron shell

Remember that we have a total of 19 electrons.

The 1st electron shell (containing s subshell) can hold up to a maximum of 2 electrons. So draw the 1st electron shell as follows:

In the above image, 1 represents the 1st electron shell that contains 1s subshell. And the green color represents the number of electrons in that subshell. This means that the 1st electron shell has a total of 2 electrons.

Since we have already used 2 electrons in the 1st electron shell, now we have 19 – 2 = 17 electrons left. So in the next step, we have to draw the 2nd electron shell.

### Draw 2nd electron shell

The 2nd electron shell (containing s subshell and p subshell) can hold up to a maximum of 8 electrons. So draw the 2nd electron shell as follows:

In the above image, 2 represents the 2nd electron shell that contains 2s and 2p subshells. And the green and orange color represents the number of electrons in that subshell. This means that the 2nd electron shell has a total of 8 electrons.

Now we have already used 10 electrons in 1st and 2nd electron shells, so we have 19 – 10 = 9 electrons left. So in the next step, we have to draw the 3rd electron shell.

### Draw 3rd electron shell

The 3rd electron shell (containing s subshell, p subshell, and d subshell) can hold up to a maximum of 18 electrons. So draw the 3rd electron shell as follows:

In the above image, 3 represents the 3rd electron shell that contains 3s and 3p subshells. And the green and orange color represents the number of electrons in that subshell. This means that the 3rd electron shell has a total of 8 electrons.

The 3rd electron shell contains only 3s and 3p subshells, and not a 3d subshell. This is because according to the aufbau principle, the 4s subshell is filled first and then 3d, 4p, 5s… and so on.

Now we have already used 18 electrons in 1st, 2nd, and 3rd electron shells, so we have 19 – 18 = 1 electron left. So in the next step, we have to draw the 4th electron shell.

### Draw 4th electron shell

The 4th electron shell (containing s subshell, p subshell, d subshell, and f subshell) can hold up to a maximum of 32 electrons. So draw the 4th electron shell as follows:

In the above image, 4 represents the 4th electron shell that contains 4s subshell. And the green color represents the number of electrons in that subshell. This means that the 4th electron shell has a total of 1 electron.

That’s it! This is the final Bohr model of potassium atom as we have used all 19 electrons: 2 electrons in the 1st electron shell, 8 electrons in the 2nd electron shell, 8 electrons in the 3rd electron shell, and 1 electron in the 4th electron shell.

Next: Calcium Bohr model