The variation of the boiling point of the hydrogen halides in the order HF >  HI > HBr > HCl. What explains the higher boiling point of hydrogen fluoride?

• The electronegativity of fluorine is much higher than for other elements in the group

• There is strong hydrogen bonding between HF molecules

• The bond energy of HF molecules is greater than in other hydrogens halides

• The effect of nuclear shielding is much reduced in fluorine which polarises the HF molecules