# Chlorine valence electrons

Chlorine has 7 valence electrons.

Contents

## Methods

We can write the valence electrons of chlorine 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 chlorine on the periodic table.

Next, mark the group number of chlorine 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 chlorine is in group 17, it has 7 valence electrons.

### Using electron configuration

• First, write electron configuration of chlorine

The electron configuration of chlorine is [Ne] 3s2 3p5.

• Second, find highest energy level in electron configuration

In the above electron configuration, the highest energy level (3) is marked with green color.

• Finally, count electrons of that energy level

The 3rd energy level contains 3s and 3p subshells. There are 2 electrons in the 3s subshell and 5 electrons in the 3p subshell. So chlorine has a total of 2 + 5 = 7 valence electrons.