which chemical bond is strong bond
For example, the bond strength of NaCl (ionic) is 99 kcal/mol; the bond strength of HCl (covalent) is 103 kcal/mol, and the bond strength in methane (covalent) is 104 kcal/mol. The strongest bonds I know of are silicon-fluorine bonds, which are about 140 kcal/mol.