Question

How can I write a noble gas shorthand?

Answer 1

Noble gases are those gases in the periodic table which are having stable electronic configuration, it means in the outermost shell of the noble gases two or eight electrons are present.

Complete answer:
From the word ‘noble gas shorthand’ it is clear that you have to write the electronic configuration of any element by using noble gas configuration in place of inner shell electronic configuration.
Some rules for writing the noble gas shorthand are as follow:
-For writing the noble gas shorthand of any atom, first you have to know about the atomic number and electronic configuration of all the noble gases present in the periodic table.
-If an atom is given which belongs from the 3rd period of the periodic table and you have to write the noble gas shorthand for that atom, then you should use the symbol or electronic configuration of that noble gas which is present in the 2nd period of the periodic table for showing the inner shell electronic configuration of given atom.
Example of noble gas shorthand for magnesium (${\text{Mg}}$) is as follow:
-As we know that the atomic number of magnesium is $12$ and it is present in the 3rd period of the periodic table.
-In magnesium $12$ electrons are present and electronic configuration of ${\text{Mg}}$ is written as ${\text{1}}{{\text{s}}^{\text{2}}}{\text{,2}}{{\text{s}}^{\text{2}}}{\text{2}}{{\text{p}}^{\text{6}}}{\text{,3}}{{\text{s}}^{\text{2}}}$.
-For magnesium, you will use neon noble gas because it is present in the 2nd period of the periodic table and electronic configuration of neon is ${\text{1}}{{\text{s}}^{\text{2}}}{\text{,2}}{{\text{s}}^{\text{2}}}{\text{2}}{{\text{p}}^{\text{6}}}$.
-So, noble gas shorthand for magnesium atom is written as $\left[ {{\text{Ne}}} \right]{\text{3}}{{\text{s}}^{\text{2}}}$.

Note:
Here some of you may write the shorthand noble gas of the 3rd period, by only seeing that magnesium belongs from the 3rd period which will be wrong.