Question

. (i) how do you calculate the possible valency of an element from the electronic configuration of its atoms? (ii) calculate the valency of element x whose atomic number is 9 (cbse 2011)

Answer 1

answer i. we can count the valency of an element by knowing the no of electron in its outermost shell


ii. it's electronic configuration will be 2,7
so valency will be 8-7=1

Answer 2

Hey dear,

● Valency calculation -
- Valency of element is determined by no of electrons that can be donated/accepted by particular element.
- Using electronic configuration, number of electrons in outermost shell gives valency of an element.

● Valency of X -
- Electronic configuration of X (Z=9) is 1s2 2s2 2p5.
- X has 5 electrons in p subshell, so it can accept one electron to complete its octet.
- Therefore, valency of X is -1.


Hope this helped you...