Find out the valency of the atoms represented by the Fig. 4.3 (a) and (b).

AcademicChemistryNCERTClass 9

Atom represented by (a) has zero valency as it has 8 electrons in its valence shell making the configuration stable.

Atom represented by (b) has a valency of +1 as it has 7 electrons in its outermost shell.
It can accept 1 electron to achieve octet configuration. 

[Extra information: According to the octet rule, atoms are most stable when their valence shells are filled with eight electrons.]
Updated on 10-Oct-2022 13:32:11