Question

What is the total number of valence electrons on a phosphite ion $P{O_3}^{ - 3}$?

Answer 1

As we know that in chemistry, periodic tables play a vital role. In the periodic table there are totally $118$ elements. In the periodic table there are totally $18$ columns and $7$ rows. The columns are called groups. Hence, $18$ groups in the periodic table. The rows are called periods. Hence, totally $7$ period in the table.
Formula used:
The total number of valence electrons is dependent on the valence electrons in the atoms in the molecules or ions.
The total number of valence electrons is equal to the sum of the valence electrons in the atoms in the molecules or ions.

Complete answer:
The atomic symbol of phosphorus is $P$. The atomic symbol of oxygen is $O$.
The atomic number of phosphorus is $15$. The atomic number of oxygen is $8$.
The valence electron in the oxygen atom is six and the valency electrons in the phosphorus atom is five.
In phosphite ion, one phosphorus atom and three oxygen atoms and extra three electrons from outside.
The total number of valence electrons is equal to the sum of the valence electrons in the atoms in the molecules or ions.
The total number of valence electrons on a phosphite ion $P{O_3}^{ - 3}$ is calculated,
$= 5 + \left( {6 \times 3} \right) + 3$
$= 5 + 18 + 3 = 26$
According to the above discussion and calculation we conclude the total number of valence electrons on a phosphite ion $P{O_3}^{ - 3}$ is $26$ electrons.

Note:
We have to remember that the atomic number of the element is nothing but the number of electrons or number of protons. The mass number of the atom is nothing but the sum of the number of protons and number of neutrons. In every atom the number of protons and the number of electrons are equal. The stable electronic configuration in the second period is $10$. The stable electronic configuration in the third period is $18$.