Can a T-bond be formed without the formation of a `sigma`-bond?

Explanation

To determine whether a pi bond can be formed without the formation of a sigma bond, we need to understand the nature of these bonds and how they are formed.

### Step-by-Step Solution:

1. **Understanding Bond Types**:
- A sigma (σ) bond is formed by the head-on (or axial) overlap of atomic orbitals. This type of bond is characterized by a strong bond strength and is the first bond formed between two atoms.
- A pi (π) bond is formed by the lateral (or side-to-side) overlap of p orbitals. This bond is generally weaker than a sigma bond and is formed after a sigma bond has already been established.

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