# Selenium Bohr model

In the selenium Bohr model, the nucleus consists of 34 protons and 45 neutrons. Surrounding this nucleus are four electron shells, accommodating a total of 34 electrons.

To draw the selenium Bohr model, outline the 34 protons, 45 neutrons, and 34 electrons. Start by illustrating the nucleus, and then draw the four electron shells. The first three shells should contain 2, 8, and 18 electrons, respectively, while the fourth shell holds the remaining 6 electrons.

Contents

## Steps

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

Selenium has 34 protons, 45 neutrons, and 34 electrons.

### Draw nucleus of selenium atom

The nucleus of a selenium atom contains 34 protons and 45 neutrons. So draw the nucleus of selenium 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 34 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 34 – 2 = 32 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 34 – 10 = 24 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, 3p and 3d subshells. And the green, orange, and pink color represents the number of electrons in that subshell. This means that the 3rd electron shell has a total of 18 electrons.

Now we have already used 28 electrons in 1st, 2nd, and 3rd electron shells, so we have 34 – 28 = 6 electrons 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 and 4p subshells. And the green and orange color represents the number of electrons in that subshell. This means that the 4th electron shell has a total of 6 electrons.

That’s it! This is the final Bohr model of selenium atom as we have used all 34 electrons: 2 electrons in the 1st electron shell, 8 electrons in the 2nd electron shell, 18 electrons in the 3rd electron shell, and 6 electrons in the 4th electron shell.

Next: Bromine Bohr model