The element sodium is in the alkali metal group of the periodic table. It comprises approximately 2.8 per cent of Earth’s crust. An atomic number of any element refers to the number of electrons in an atom of that element they are having.
Step1: write the atomic number of the element
In every stable atom, the number of protons is equal to the number of electrons. Therefore, now you know the number of electrons too. Sodium’s atomic number of 11 indicates that it has an equal number of 11 protons and 11 electrons.
Step2: Write the electronic configuration for the atom of the element.
Atomic Number:- 11
Number of protons:- 11
Number of electrons:- 11
Electronic configuration:- K – 2, L-8, M-1
Sodium has 11 electrons, its first shell will be fully occupied by two electrons. That is followed by its second shell being fully occupied by eight electrons, thus leaving its third shell with just one electron