The periodic trend in atomic radius ● As we go left to right across the period the size of the atom decrease.
● This is because the nuclear charge increases while moving from left to right.
● The nuclear charge attracts electrons and hence reduces the atomic radius (or atomic size).
● B, C, N, O belongs to the same period (IInd Period).
● We can see this in periodic table the arrangements of these atoms from left to right is B, C, N, O. So, B being at the leftmost among them has the highest atomic radius.
B > C > N > O is the correct sequence.