A sigma bond is always stronger than pi-bond because the extent of overlapping of atomic orbitals along the internuclear axis is greater than sideways overlapping.
So, Sigma bonds require more energy than π bonds to break.
The pi bonds are weaker than sigma bonds and easily breaks. So, double and triple bonds can easily break their pi bonds to become a single bond.
A pi bond is a weaker chemical covalent bond than a sigma bond (since π bonds have a smaller overlap between the orbitals), but when it is put with a sigma bond it creates a much stronger hold between the atoms, thus double and triple bonds are stronger then single bonds.
Sigma bonds are never broken or made, because of this atoms must maintain their same position. All resonance contributors must have the same molecular formula and net charge.
A hydrogen bond is the chemical bond that is the easiest chemical bond to break.
In the sigma bond, the overlapping is maximum whereas in the pi bond the overlapping is minimum. So, pi bond is weaker than sigma bond.
In chemistry, sigma bonds (σ bonds) are the strongest type of covalent chemical bond. They are formed by head-on overlapping between atomic orbitals.
So, in conclusion the ionic bonds are strongest among ionic, covalent and hydrogen bonds.
Intramolecular covalent bonds, being around 98 percent stronger than intermolecular bonds, are the hardest to break and are very stable. It should be clear that since molecules exist, covalent bonds are stable. However when enough energy is provided to a molecule, the bonds may be broken.
This occurs when the un-hybridized (filled) p orbitals of each respective atom overlap to form a higher electron density between the two atoms outside of the established sigma bond. This bonding will also create an anti bonding orbital. Once this orbital is filled, the bond between the 2 atoms breaks.
The pi bond is formed by the lateral or sideway overlapping of orbitals. The strength of bond depends on the bond length. Higher the bond length higher is the energy required for the bond breaking.
Average bonds values are not as accurate as a molecule specific bond-dissociation energies. Double bonds are higher energy bonds in comparison to a single bond (but not necessarily 2-fold higher). Triple bonds are even higher energy bonds than double and single bonds (but not necessarily 3-fold higher).
A double or triple bond is stronger than a single bond because it holds the atoms closer together and makes it more difficult to break. So, a double bond requires more energy to break the bonds as compared to a single bond.
Therefore, the order from strongest to weakest bond is Ionic bond > Covalent bond > Hydrogen bond > Vander Waals interaction.
Generally, ionic bonds are much stronger than covalent bonds. In ionic bonds, there is complete transfer of electrons between elements to form a stable compound. While in covalent bond, there is only sharing of electrons between two elements to form a stable compound.
The ionic bond is generally the weakest of the true chemical bonds that bind atoms to atoms.
Hydrogen Bonds
Weaker bonds can also form. These are attractions that occur between positive and negative charges that do not require much energy to break. Two weak bonds that occur frequently are hydrogen bonds and van der Waals interactions.
Because the pi bond has less electron density between the atoms, it is of higher energy in the MO diagram and is weaker than the sigma bond.
The S−S bond has highest energy and highest bond strength For example, the bond energies of S−S and O−O bond are 49 and 33 kcal/mol respectively.
Covalent bonds are formed by the sharing of electrons between nuclei. Ionic bonds are generally stronger than covalent bonds because of the coulombic attraction between ions of opposite charges. Hence ionic chemical bonds will need more energy to break.
The electrons present in the nuclei of an atom in a pi bond are far away from the positively charged atoms, and thus this structure makes the pi bond unstable and easier to break.
Pi bonds would break first because their electrons are more spread out than those of sigma bonds. The electrons in a sigma bond are directly between the two nuclei and are harder to break.
Sigma σ is a strong bond while pi is a weak bond.