The use of diamond in abrasives is due to its

Step 1: Analyze the question The question asks which property of diamond makes it suitable for use in abrasives (materials used for grinding, cutting, and polishing).

Step 2: The concept An abrasive works by scratching or wearing away other materials. To do this, it must be harder than the material it is acting on. Diamond is a giant covalent (macromolecular) structure in which each carbon atom is bonded to four others by strong covalent bonds in a rigid tetrahedral arrangement. This gives diamond its exceptional hardness. It is the hardest known natural substance, rated 10 on the Mohs scale.

Step 3: Evaluate the options

• A. High melting point: Diamond does have a high melting point, but this is not what makes something an abrasive. It matters for heat resistance, not for grinding or cutting.
• B. Hardness: This is the property that allows diamond to cut, grind, and polish other materials, such as in diamond-tipped drill bits and saw blades. ✔
• C. Octahedral shape: This describes the crystal form, which has no bearing on abrasive action.
• D. Durability: This is a vague, general term. Durability is a consequence of hardness rather than the direct reason.

Step 4: Answer

Tip: Link uses to properties for the carbon allotropes:

• Diamond: hardness leads to cutting and abrasives
• Graphite: soft, layered, and conducts electricity, so it is used as a lubricant and in electrodes