Question

Which one of the given statements is correct?

• A. van der Waal's bonding is absent in silicate minerals
• B. Sulfide minerals form by covalent bonding between metal and sulfur
• C. Silicate minerals have a significant component of metallic bonding
• D. Metal-sulfide formation does not involve splitting of d-orbitals

Answer 1

The Correct Option is B

To determine the correct statement from the given options, let's consider each statement and evaluate its accuracy based on geological chemistry principles:

1. van der Waal's bonding is absent in silicate minerals: - This statement is incorrect. Van der Waal's forces are weak intermolecular forces, and while they are not the primary bonding type in silicate minerals (which usually involve ionic and covalent bonds), they can be present in certain conditions affecting mineral properties such as cleavage. Thus, stating they are absent is incorrect.
2. Sulfide minerals form by covalent bonding between metal and sulfur: ✓ This statement is correct. Sulfide minerals typically form through covalent bonding between metals and sulfur. Sulfur often forms covalent bonds with metals in many sulfide minerals (e.g., pyrite, galena), reflecting the moderate difference in electronegativity between the metal and sulfur. Therefore, this is the correct statement.
3. Silicate minerals have a significant component of metallic bonding: - This statement is incorrect. Silicate minerals are primarily composed of silicon and oxygen, and the bonding is typically ionic or covalent, not metallic. Metallic bonding is characterized by a sea of delocalized electrons and is usually found in metals, not in silicate minerals.
4. Metal-sulfide formation does not involve splitting of d-orbitals: - This statement is incorrect. Metal-sulfide formation often involves transition metals, which can have d-orbitals. The electron arrangement and splitting of d-orbitals (as seen in crystal field theory) can be significant in determining mineral properties like color and magnetism.

In conclusion, the correct statement is that "Sulfide minerals form by covalent bonding between metal and sulfur."