Question

What are horizontal rows in the periodic table known as?

Answer 1

Periodic Table

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

Examples

• Boron, Carbon and nitrogen are present in same period that is period number $2$.
• Sodium, Potassium and Lithium are present in same group that group number $1$.

So, horizontal rows in the periodic table are known as periods.