Answer:
hydrogen bonds are very weak and can only occur when polar covalent bonds are present
Step-by-step explanation:
Hydrogen bonds are weak intermolecular interactions that occur when hydrogen is covalently bonded to a highly electronegative atom.
Owing to the difference in electro negativity between hydrogen and the highly electronegative atom, the bond is a polar covalent bond.
This hydrogen bond is a weak bond but accounts for properties such as high melting and boiling points of small molecules such as water and ammonia.