How to Find the Valence Electrons for H2O (Water)?
The total number of electrons in the last orbit of an element is called the valence electrons of that element. Two or more elements combine to form compounds.
The valence electrons of a compound are the sum of the total valence electrons of each element in that compound. Water consists of two basic atoms. One is a hydrogen atom and the other is an oxygen atom.
The valence electrons of water are the sum of the total valence electrons of hydrogen and oxygen in the compound H2O. The water compound has a total of eight electrons in the last orbits of hydrogen and oxygen.
Hence, the total number of valence electrons in water is eight. To determine the valence electrons of a compound, the number of valence electrons in each element of the compound must be known.
This article discusses in detail how to determine the valence electrons of water very easily. Hopefully, after reading this article you will know more about this topic.
How to easily determine the number of valence electrons of H2O?
The symbol form of water is H2O. To determine the valence electrons of H2O, it is first necessary to know the valence electrons of the oxygen and hydrogen atoms. To determine the valence electrons of water we have to follow two steps. It is shown below:
Step 1: Determine the valence electrons of hydrogen and oxygen atoms
The atomic number of hydrogen is 1. So its total number of electrons is one. The electron configuration of hydrogen shows that it has one electron in its last orbit.
We already know that the electrons in the last orbit of an element are the valence electrons of that element. Therefore, the valence electrons of hydrogen are one.
On the other hand, the atomic number of oxygen is 8. So its total number of electrons is eight. The electron configuration of oxygen shows that it has six electrons in its last orbit. Therefore, the valence electrons of oxygen are six.
Step 2: Determine the total number of valence electrons in the water compound
Water is a compound. It is composed of two hydrogen atoms and an oxygen atom. Therefore, adding the valence electrons of two hydrogen atoms and the valence electrons of an oxygen atom can easily determine the valence electrons of water.
Mathematical Analysis:
H2O
= (1×2) + 6
= 8
Hydrogen (H) | Oxygen (O) | Water (H2O) |
1 | 6 | 8 |
From the above mathematical analysis, we can see that the total number of electrons in the outermost orbit of water is eight. Therefore, the valence electrons of water are eight.
Why do you need to know the valence electrons of an element?
In addition to knowing the number of electrons of an element, it is also necessary to know the number of valence electrons of that element. The number of valence electrons of an element carries important properties of that element.
Many important properties of elements and compounds can be determined by valence electrons. Some important features are mentioned below:
- Determining the element’s position in the periodic table
- Determining the number of groups of elements in the periodic table
- Determining Valency
- Lewis dot formation
- Determination of the molecular structure of the compound
- Determination of bond pairs and non-pair electrons of compounds
Valence electrons are related to the characteristics of a compound. So we need to know the valence electrons of all the elements to determine the properties of compounds.