Study the variation in the atomic radii of first group elements given below and arrange them in an increasing order.

Period $\mathrm{I}$ elements	$\mathrm{Na}$	$\mathrm{Li}$	$\mathrm{Rb}$	$\mathrm{Cs}$	$\mathrm{K}$
Atomic radius (pm)	$186$	$152$	$244$	$262$	$231$

 

Study the variation in the atomic radii of first group elements given below and name the elements which have the smallest and the largest atoms.

How does the atomic size vary as you go down a group?

Classify elements of the third period and as metals and non-metals.

On which side of the Periodic Table do you find the metals?

On which side of the Periodic Table do you find the non-metals?