Why hydrogen bonds are stronger?
least electronegative hydrogen and most electronegative F O N CL Br JOIN TOGETHER AND form a strong bond
true Yes, they are. Covalent bonds are the strongest type of intramolecular bond, and hydrogen bonds are the strongest type of intermolecular bond. However, intramolecular bonds (within molecules or compounds) are ALWAYS stronger that intermolecular bonds (between molecules), so covalent bonds are much stronger that hydrogen bonds.
It's not that the individual hydrogen bonds are stronger but rather there are more of them. Between A and T there are two hydrogen bonds, between G and C there are three hydrogen bonds. The additional hydrogen bond between G and C does mean that the bonding between G and C is much stronger then that between A and T and requiring of significantly more energy to break.
Ionic bonds are far stronger than hydrogen bonds. Ice is held together by hydrogen bonds, and table salt, which is sodium chloride (NaCl), is held together by ionic bonds. You can hammer on ice and break the hydrogen bonds holding it together with relative ease. But you can hammer all day on salt, turn it to a white powder, and not break the sodium-chlorine bonds (those ionic bonds) in any molecules of salt by doing…