How does the atomic radius of the elements change on going (i) from left to right in a period, and (ii) down a group in the Modern Periodic Table? Give reason in support of your answer.

 

Answer

ATOMIC RADII ACROSS GROUP AND PERIOD - Teachoo.png

As we go from left to right in a period,

  • The nuclear charge increases but the number of shells increases

so this tends to pull the electrons closer to the nucleus and atomic radius decreases.

As we move down a group,

  • The number of shells increases , the electrostatic attraction between the nucleus and the outermost shell electrons decreases and so, the atomic radius increases.
Go Ad-free
Maninder Singh's photo - Co-founder, Teachoo

Made by

Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 14 years and a teacher from the past 18 years. He teaches Science, Economics, Accounting and English at Teachoo