Answers

2015-08-19T18:42:08+05:30
Valency would be same of particular group no.
ex-group 1 will have valency  of 1
group 2 - 2
 group3 - 3
group 4 - 4
group 5 - 3  
group 6 - 2
group 7 -1
group 8 - 0
0