Can u please explain calculation of valency - English - E-mail

Question

Can u please explain calculation of valency

Priyanka Sahu · Accepted Answer

Dear Student,
The electrons present in the last shell determine the valency of
a particular element
If the number of valence electrons ≤4: valency = number of
valence electrons
If the number of valence electrons >4: valency = 8 - number
of valence electrons
For e g

Group in periodic table
Number of valency electrons
valency

1
1
1

2
2
2

13
3
3

14
4
4

15
5
3, 5

16
6
2, 6

17
7
1, 7

18
8
0, 8

For your convenience, I am providing two examples to show how
valency of any element can be found out
If you consider the element aluminium and try to write its
electronic configuration, then it is 2, 8, 3 the valency is equal
to 3
However, for element oxygen having electronic configuration 2, 6
the valency is 8 - 6 = 2

Regards

Group in periodic table	Number of valency electrons	valency
1	1	1
2	2	2
13	3	3
14	4	4
15	5	3, 5
16	6	2, 6
17	7	1, 7
18	8	0, 8