Diamonds can be synthesised by subjecting pure carbon to :

Correct option is B

The correct answer is (b) Very high pressure and high temperature

Explanation:

• Diamonds are formed naturally in the Earth's mantle under extreme conditions of high pressure (above 5 GPa) and high temperature (above 1,500°C).
• Synthetic diamonds are produced in laboratories using two major methods:

High-Pressure High-Temperature (HPHT) Method:

• Mimics natural diamond formation.
• Pure carbon is placed in a high-pressure chamber and subjected to extreme heat, converting it into a diamond.

Chemical Vapor Deposition (CVD) Method:

• Uses a carbon-rich gas (e.g., methane) in a low-pressure chamber to deposit layers of carbon atoms onto a substrate.

Information Booster:

Properties of Diamond:

• Hardest naturally occurring material.
• Excellent thermal conductor.
• Used in jewelry, cutting tools, semiconductors, and scientific applications.

Formation of Natural Diamonds:

• Occurs at depths of 140-190 km inside the Earth's mantle.
• Volcanic eruptions bring them closer to the surface in kimberlite pipes.