They are the measurable properties of a bond and these are associated only with covalent bond.
- Bond length: It is the average distance between the centre of two bonded atoms .
Factors on which bond length depends:
- Size of the atoms: Bigger the size of the atom more is the bond length.
- Multiplicity of bond: If there is a single bond, bond length is longer as compared to bond length in double or triple bond.
- That is the reason bond length of alkanes is more than alkenes which is further more than alkynes.
- Bond angle: It is an average distance between the orbital of the atoms surrounding the central atom.
- Bond enthalpy: It is the amount of energy required to break one mole of bonds.
Factors on which it depends:
- Bond length: More the bond length, lesser is the force of attraction hence, lesser will be bond enthalpy.
- Multiplicity of bond: More is the multiplicity of bonds, more is the bond enthalpy.
For example: Nitrogen is inert because of its high bond dissociation or bond enthalpy.
Note: If we have more than two atoms in molecule, than bond energy is called as average bond energy .It is calculated by adding the bond energies of all the bonds involved.
For example: In water
- Bond order: It is the number of bonds present between two atoms.
For example: In H2 (bond order is 1 )
In oxygen molecule (bond order is 2)
In nitrogen molecule bond order is 3)
- In Iso-electronic species: The bond order is same.
Example: In Fluorine and O22- the electrons are 18 and bond order is same that is 1.