Teaching BPSC बिहार माध्यमिक TGT (9 to 10) शिक्षक भर्ती 4.0 Mock Test General Science Chemistry Classification of Elements and Periodicity in Properties
The electronegativity of N, O, P and S increases in the order
1
P < S < N < O
2
P < N < O < S
3
S < P < N < O
4
More than one of the above
5
None of the above