The strength of a covalent bond is measured by the amount of energy needed to break the bond or the bond enthalpy.The shorter the bond the greater the bond strength as the electrostatic attraction is greater.
The strength of a bond between two atoms increases as the number of electron pairs in the bond increases. Generally, as the bond strength increases, the bond length decreases.
The strength of a bond between two atoms increases as the number of electron pairs in the bond increases. Generally, as the bond strength increases, the bond length decreases.
| bond | H-F | H-Cl | H-Br | H-I |
| bond length Å | 0.917 | 1.275 | 1.415 | 1.609 |
| bond strength kJ/mol | 571 | 432 | 366 | 298 |