Due to covalent bonding, the transitional metals are

Options

A. Lustrous
B. Conductor
C. Hard and brittle
D. Ductile

Explanation

**Step-by-Step Text Solution:**

1. **Understanding Covalent Bonding in Transition Metals:**
Transition metals are known for their ability to form covalent bonds due to their partially filled d-orbitals. This allows them to share electrons with other atoms, leading to the formation of strong covalent bonds.

**Hint:** Recall that covalent bonding involves the sharing of electrons between atoms.

2. **Properties of Transition Metals:**
Due to the presence of covalent bonds, transition metals exhibit several distinct physical properties:
- **Hardness and Brittleness:** The strong covalent bonds contribute to the hardness of transition metals. However, this also makes them brittle, as they can fracture under stress.

**Hint:** Think about how strong bonds can affect the structure and stability of a material.

3. **High Melting and Boiling Points:**
Transition metals typically have high melting and boiling points. This is a result of the strong covalent bonds that require a significant amount of energy to break.

**Hint:** Consider how the strength of the bonds influences the amount of energy needed to change the state of a substance.

4. **Ductility:**
Despite being hard and brittle, many transition metals are also ductile. This means they can be drawn into wires. The ability to be deformed without breaking is due to the presence of metallic bonding in addition to covalent bonding.

**Hint:** Reflect on how different types of bonding can coexist in a material and affect its properties.

5. **Conclusion:**
In summary, due to covalent bonding, transition metals are characterized by their hardness, brittleness, high melting and boiling points, and ductility. These properties arise from the strong interactions between atoms facilitated by covalent bonds.

**Hint:** Summarize the key properties and think about how they relate to the nature of bonding in transition metals.

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