So you have seen the above image by now, right?
Awesome! You can see that barium has 2 valence electrons.
But how can you say that Barium has 2 valence electrons
How can you find these valence electrons?
Let’s discuss this in short.
Barium has 2 valence electrons because there are 2 electrons present in the outermost shell of the Barium (Ba) atom.
Now let’s see how you can easily find the valence electrons of Barium atom (Ba).
If you don’t want to read the texts, then you can also watch this video.
How to find the Valence Electrons? (2 Methods)
In order to find the valence electrons of Barium atom (Ba), you can use two methods.
Method 1: From the Periodic Table
To find out the valence electrons of Barium, you have to see the position of barium in the periodic table.
More specifically, you have to see the group wise position of Barium element in the periodic table.
From the above image, you can see that the Barium (Ba) is present in the group 2 of periodic table.
(Note: Group 2 is also called group 2A).
So, as the barium element is present in group 2, it has 2 valence electrons.
In this way, by knowing the position of barium element in periodic table, you can easily find its valence electrons.
Now let’s see another method for finding the number of valence electrons in barium.
Method 2: From the Electron Configuration
If you want to find the valence electrons of barium from its electron configuration, then you should know its electron configuration first.
Now there are many methods to write the electron configurations, but here I will show you the easiest method, i.e by using Aufbau principle.
Aufbau principle: The Aufbau principle simply states that the orbitals with the lower energy are filled first and then the orbitals with higher energy levels are filled.
According to the Aufbau principle, the orbitals are filled in the following order:
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p, and so on.
Also the maximum number of electrons that can be accommodated in s, p, d & f orbitals are mentioned in the below table.
|Maximum capacity of electrons 
Now let’s try to find the electron configuration of Barium by using the Aufbau principle.
Electron Configuration of Barium:
Follow the steps mentioned below to get the electron configuration of Barium.
- To write the electron configuration of barium, we should first know the total number of electrons present in a barium atom.
- The barium atom has a total of 56 electrons because its atomic number is 56 and it is a neutral atom. 
- Now we have to fill these 56 electrons in the atomic orbitals according to the Aufbau principle.
- According to the Aufbau principle, the electrons will be filled first in 1s orbital, then in 2s orbital, then in 2p orbital, and so on…
- So from the Aufbau principle, we can get the electron configuration of the barium atom as 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 6s2. 
Now in this electron configuration of barium, we have to see the total number of electrons present in the highest energy level.
You can see in the electron configuration of barium (1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 6s2) that the highest energy level is 6. And the total number of electrons present in this energy level is 2.
So by knowing the electron configuration, we have found that the Barium has 2 valence electrons.
I hope you have understood the methods of finding the valence electrons in barium.
Jay is an educator and has helped more than 100,000 students in their studies by providing simple and easy explanations on different science-related topics. With a desire to make learning accessible for everyone, he founded Knords Learning, an online learning platform that provides students with easily understandable explanations.
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