Chemistry Chapter 4 : Bond energy and Bond length

Definition of bond energy

The energy required to break one mole of a particular covalent bond in the gaseous state.

Definition of bond length

Intermolecular distance between the nuclei of two covalently bonded atoms

Bond energy and Bond length

With the increase of atomic radius, bond length increases so bond strength decreases so less energy is required to break the bonds.

Thermal stability of hydrogen halides

Thermal stability decreases down the group
Atomic radius of halogens increase
Bond length increase
Bond strength decreases
Less energy is required to break the bonds

Surface Tension

Tension is caused by the attraction of particles in the liquid surface

Water molecules on the surface attract sideways and downwards but not upwards

This pulls the water molecules into the liquid and tightens the surface creating surface tension