‘Valency is also the number of electrons – donated or accepted by an atom so as to achieve the stable electronic configuration of the nearest noble gas’. With reference to this definition –
State what is meant by ‘stable electronic configuration’.
Stable electronic configuration means to have 2 electrons in the 1st [or K] outermost shell-like He – [Duplet].
8 electrons in outermost orbit like other nearest noble gas – [Octet].