question_answer

  Describe the properties of O, S, Se, Te and Po with reference to (i) metallic properties (ii) catenation (iii) thermal stability of hydrides (iv) oxidation states (v) allotropy.

Answer:

  (i)  bond enthalpy is higher than  bond enthalpy So,  is exothermic compound but  is endothermic compound (ii) Nitrogen does not form pent chloride like phosphorus due to the absence of d-orbitals.