Question

An element has its electronic configuration as $2,8,2$. Now answer the following question:
To which period does does this element belong ?

Answer 1

Period number of an element is equal to the number of total shells that contain electrons in the atom.

$2,8,2$

$K,L,M$

$\therefore$ Three shells contains electrons.

$\therefore$ This element belongs to $3rd$ period.