# Bonding Force

Last updated: August 5, 2020

## What Does Bonding Force Mean?

Bonding forces are forces of attraction or repulsion which act between neighboring particles such as atoms, molecules or ions. Bonding force determines the elastic modulus (or Young's modulus) of a material (how stiff a material is).

The strength of chemical bonds varies considerably; there are "strong bonds" such as covalent or ionic bonds, and "weak bonds" such as dipole-dipole interactions and hydrogen bonding.

Since interaction energy and bonding force are directly related, the stronger the bond energy, the harder is to move the atoms, such as to melt the solid or to evaporate its atoms.

## Corrosionpedia Explains Bonding Force

Bonding forces are the sum of attractive forces and repulsive forces between atoms, molecules or ions. In a solid material this includes:

• Attractive forces which keep the atoms together, forcing them to form a solid
• Repulsive forces which come into play when a solid is compressed

Such forces, however, act in the case of liquids also and even in a single molecule. But mere existence of these forces between atoms does not guarantee the formation of a stable chemical bond.

This may be established by considering two atoms, A and B, exerting attractive and repulsive forces on each other such that the bonding force, F, between the atoms may be represented as:

• The first term represents the attractive force and the second term the repulsive force. Near the equilibrium position the second term must increase more rapidly for diminishing value of r than does the first, and N is necessarily greater than M.

When the atoms reach a critical distance (r0), the attractive and repulsive forces cancel each other and the atoms are at their equilibrium distance. Sometimes it is easier to deal with potential energies (E) rather than forces. The equilibrium spacing occurs when the bond energy is a minimum. This is when the net forces between the two atoms is zero, i.e. at the equilibrium spacing, F(r) = 0 when r= r0. As the interatomic distance increases, the force required increases linearly.

In general, stronger bonds enable a material to withstand higher temperatures before the bonds break and the material melts or softens. 