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Define covalent bond - Leaving Cert Chemistry - Question c - 2005
Question c
Define covalent bond. Distinguish between a sigma (σ) and a pi (π) covalent bond.
Worked Solution & Example Answer:Define covalent bond - Leaving Cert Chemistry - Question c - 2005
Step 1
Define covalent bond.
Answer
A covalent bond is defined as the chemical bond that involves the sharing of one or more pairs of electrons between atoms. This interaction leads to the formation of a stable balance of attractive and repulsive forces between atoms, allowing them to achieve a more stable electron configuration.
Step 2
Distinguish between a sigma (σ) and a pi (π) covalent bond.
Answer
A sigma (σ) bond is formed by the end-on (or head-on) overlap of atomic orbitals, creating a bond with a single nodal plane. This type of bond allows for free rotation around the bond axis.
In contrast, a pi (π) bond is formed by the side-on (or sideways) overlap of p-orbitals, which results in two nodal planes. Pi bonds typically accompany sigma bonds in double or triple bonding scenarios and restrict rotation due to the overlapping orbitals.