The increasing order of the atomic radius of $\mathrm{Si}, \mathrm{S}, \mathrm{Na}, \mathrm{Mg},…

The increasing order of the atomic radius of $\mathrm{Si}, \mathrm{S}, \mathrm{Na}, \mathrm{Mg}, \mathrm{Al}$ is
  1. $\mathrm{S} < \mathrm{Si} < \mathrm{Al} < \mathrm{Mg} < \mathrm{Na}$
  2. $\mathrm{Na} < \mathrm{Al} < \mathrm{Mg} < \mathrm{S} < \mathrm{Si}$
  3. $\mathrm{Na} < \mathrm{Mg} < \mathrm{Si} < \mathrm{Al} < \mathrm{S}$
  4. $\mathrm{Na} < \mathrm{Mg} < \mathrm{Al} < \mathrm{Si} < \mathrm{S}$

Solution

As we move from left to right in a period, effective nuclear charge increases. Due to this atomic radius decreases. Thus, correct order of atomic radii of $3^{\text {rd }}$ period elements is $\mathrm{Na}>\mathrm{Mg}>\mathrm{Al}>\mathrm{Si}>\mathrm{S}$

Asked in: JEE-TOPICTESTS-CHEMISTRY

Practice more CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES questions on Aicharya