Why does NH3 form hydrogen bond but 'PH3 does not?

Explain why inspite of nearly the same electronegativity, oxygen forms hydrogen bonding while chlorine does not.

Why does hydrogen occur in a diatomic fom rather than in a monoatomic form under nomal conditions?

Which of the following statements is/are correct on the basis of hydrogen bond ? (1) KHF2 exists but KHCl2 does not. (2) Boiling point order of hydrogen halides is HF>HI>HBr>HCl (3) CCl3 CH (OH) 2 and o- nitrophenol show intermolecular hydrogen bond (4) All are correct

Why does Be resemble Al?

Why does R_3P=0 exist but R_3N=0 does not. [R = alkyl group]?

In the formation of hydrogen chloride does the oxidation number of hydrogen increases or decrease ?

Why formic acid(HCOOH) does not give HVZ reaction but CH3COOH does

CIF_3 exists but FCI_3 does not. Why?