Which element of group 13 forms covalent compounds only

Explanation

To determine which element of group 13 forms covalent compounds only, we can analyze the properties of the elements in this group.

### Step-by-Step Solution:

1. **Identify Group 13 Elements**:
Group 13 of the periodic table consists of the following elements: Boron (B), Aluminum (Al), Gallium (Ga), Indium (In), and Thallium (Tl).

2. **Analyze the Nature of Compounds Formed**:
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