Question

What is the common thing in the elements belonging to the same group?

Answer 1

Group

• The periodic table involves $18$ vertical columns and $7$horizontal rows.
• The horizontal rows are referred as periods.
• The vertical columns are referred to as groups.

Common thing in the elements belonging to the same group

• The properties that reappear at regular intervals, or there is a gradual increase or decrease at regular intervals are called periodic properties. And the phenomenon of periodic properties is known as periodicity.
• Periodicity occurs due to the same number of electrons in the outermost orbit or the recurrence of a similar electronic configuration.
• For example, lithium $\left(\mathrm{Li}\right)$ and sodium$\left(\mathrm{Na}\right)$ belong to the first group.
• So, the number of valence electrons in lithium and sodium is $1$.