Question

How do you write the noble-gas electron configuration of nitrogen?

Answer 1

The atomic number of nitrogen is 7 and has 7 electrons in the element. Nitrogen is placed in the second periodic table.

Complete answer:
In the question it is asked to write the noble-gas electron configuration of nitrogen atoms. From the lower classes we have been writing the electronic configuration of the element by filling the number of electrons present in the atom with respect to the increasing order of their energy of the orbitals present in various shells of an atom. Now we should know that, what is meant by writing the noble-gas electronic configuration?
The way of writing the noble-gas electronic configuration means we condense the formulae of electronic configuration of atoms by writing the noble gas that belongs to the period above the element’s period in a square bracket and then write the other electrons present in the atom.
We can represent this way of writing electronic configuration as,
$\text{Electronic}\,\text{configuration=}\left[ \text{noble}\,\text{gas} \right]\text{other}\,{{\text{e}}^{\text{-}}}\text{s}$
Now let’s solve this problem with the data know,
We know that the atomic number of N is 7 and hence the number of protons and atoms present in the atom will be 7.
Now take a look at the position of the N in the periodic table. The nitrogen is placed with the second period and we know that the period number represents the total number of shells present in the atom. So N place in the second period means the N is having two shells and let’s write its general configuration by distributing the electrons in the various orbitals of the atoms at various energy levels.
$\text{Electronic}\,\text{configuration}\,\text{of}\,\text{N=1}{{\text{s}}^{\text{2}}}\text{2}{{\text{s}}^{\text{2}}}\text{2}{{\text{p}}^{\text{3}}}$ $\text{Electronic}\,\text{configuration}\,\text{of}\,\text{N=}\left[ \text{He} \right]\text{2}{{\text{s}}^{\text{2}}}\text{2}{{\text{p}}^{\text{3}}}$
Now we should know the atomic number of the noble gas present in the period just above to the period in which the element belongs too.
The noble gas group elements are placed in the group 18 in the periodic table. Hence now we know that the He is the noble gas present in the first period is He which has an atomic number of 2.
So now we write a condensed equation for the electronic configuration by inserting the noble gas configuration and then placing the other electrons and by which we obtain the electronic configuration is called a noble-gas electronic configuration.
Let’s write the configuration,$\text{Electronic}\,\text{configuration}\,\text{of}\,\text{N=}\left[ \text{He} \right]\text{2}{{\text{s}}^{\text{2}}}\text{2}{{\text{p}}^{\text{3}}}$

Note:
We should know the atomic number of the atom given to know the number of electrons and we should know to which group and period does belong too.
If we know the period of the element only we could predict which noble gas should be inserted for writing the electronic configuration or we must know the atomic numbers.
It is a must to know the atomic number of noble gases and remember the group completely to write the noble –gas configuration.