A sigma bond is formed by the overlapping of :A s-s orbital alone B s and p orbitals alone C s-s, s-p or p-p orbitals along internuclear axis D None of these

To understand the formation of a sigma bond, we need to investigate how atomic orbitals overlap. The correct answer involves identifying the types of orbitals that can contribute to sigma bonding.

1. Breaking Down the Problem

• What is a sigma bond?
• What types of orbitals can overlap to form a sigma bond?

2. Relevant Concepts

• A sigma bond is characterized by the head-on overlap of atomic orbitals.
• Orbital types involved in sigma bond formation include:
  • s-s orbitals
  • s-p orbitals
  • p-p orbitals (specifically when oriented along the internuclear axis)

3. Analysis and Detail

• Option A (s-s orbital alone): This suggests that only s-s overlapping results in a sigma bond, which is too limiting.
• Option B (s and p orbitals alone): This does not account for p-p orbital contributions.
• Option C (s-s, s-p or p-p orbitals along internuclear axis): This correctly includes all forms of overlap that can lead to sigma bonds.
• Option D (None of these): Implies that none of the provided answers are correct.

4. Verify and Summarize

The most comprehensive definition includes all types of relevant orbital overlap that can form a sigma bond. Thus, the correct answer is:

Final Answer

C: s-s, s-p or p-p orbitals along the internuclear axis.