Question

Which element has the smallest atomic radius (here)?

• A. $Na$
• B. $Mg$
• C. $B$
• D. $N$

Answer 1

Answer: (D)

$N$

All given elements are present in second and third periods. The atomic size decreases towards the right in a period as effective nuclear charge increases. Down the group size increases due to addition of a new shell.

Thus the order of size is $Na>Mg>B>N$.

Hence the smallest is $N$ (Nitrogen).