Question

Name the elements which have the follow­ing electronic configuration: $2,8,1$

Answer 1

Given:

Electronic configuration $=2,8,1$

Formula used:

Atomic number $=$Number of electrons in the neutral atom.

Calculate the number of electrons:

As the electronic configuration $=2,8,1$

Total number of electrons$=11$

Find atomic number:

The number of electrons in an atom is equal to the atomic number of the element

Hence, the Atomic number $=11$

Identify the element:

The element with the atomic number 11 is sodium. Its chemical symbol is $\mathrm{Na}$.