# Selenium valence electrons

Selenium has 6 valence electrons.

Contents

## Methods

We can write the valence electrons of selenium using two different methods:

#1 Using periodic table
#2 Using electron configuration

Let’s break down each method in detail.

### Using periodic table

Get the periodic table having the chemical elements marked on it as mentioned above.

Now mark the location of selenium on the periodic table.

Next, mark the group number of selenium on the periodic table.

The valence electrons of each main-group element can be determined by the column in which it is located.

(i.e., all group 1 elements have 1 valence electron, all group 2 elements have 2 valence electrons, skip the transition metals… then, all group 13 elements have 3 valence electrons, all group 14 elements have 4 valence electrons, and so on up to group 18 elements)

Since selenium is in group 16, it has 6 valence electrons.

### Using electron configuration

• First, write electron configuration of selenium

The electron configuration of selenium is [Ar] 4s2 3d10 4p4.

• Second, find highest energy level in electron configuration

In the above electron configuration, the highest energy level (4) is marked with green color.

• Finally, count electrons of that energy level

The 4th energy level contains 4s and 4p subshells. There are 2 electrons in the 4s subshell and 4 electrons in the 4p subshell. So selenium has a total of 2 + 4 = 6 valence electrons.