Teaching BPSC बिहार माध्यमिक TGT (9 to 10) शिक्षक भर्ती 4.0 Mock Test General Science Chemistry Classification of Elements and Periodicity in Properties
What is the valency of the element that has atomic no 12?
1
1
2
2
3
3
4
More than one of the above
5
None of the above