Q.

Which of the following is incorrect

1 Acidic order: N2O5>P2O5>As2O5>Sb2O5>Bi2O5  
2 Stability: Black-P>Red-P>White-P  
3 Covalent Radius: Po>Te>Se>S>O  
4 Ionisation Energy S>O>Se>Te>Po  

Ans.

(4)

The correct order for Ionisation Energy is O>S>Se>Te>Po