What is the second hardest material known?

Carborundum

The correct answer is option 2. Carborundum.

Carborundum refers to silicon carbide (SiC), which is a compound made up of silicon and carbon. It is known for its hardness and is widely used as an abrasive material. While diamond is the hardest known natural material, carborundum (silicon carbide) is often considered the second hardest material.

Here's a brief explanation:

1. Diamond (Hardest Material):

Diamond is composed of carbon atoms arranged in a crystal lattice structure, and it is known for its exceptional hardness. It is the hardest naturally occurring material and can only be scratched by another diamond.

2. Carborundum (Silicon Carbide - SiC):

Carborundum is an artificial compound made by combining silicon and carbon. It is exceptionally hard and has properties that make it suitable for various industrial applications, particularly as an abrasive material in cutting, grinding, and polishing.

3. Hardness Comparison:

While diamond is at the top of the hardness scale with a Mohs hardness of 10 (the highest possible), carborundum has a Mohs hardness of approximately 9-9.5. This places carborundum just below the diamond in terms of hardness.

4. Industrial Applications:

Carborundum is extensively used in manufacturing, cutting tools, grinding wheels, and abrasives due to its hardness and wear-resistant properties. It is valued for its ability to withstand high temperatures and maintain its hardness under extreme conditions.

It's important to note that the hardness of materials is often assessed using the Mohs scale, which ranges from 1 (softest) to 10 (hardest). While carborundum is not as hard as diamond, it is a remarkable material with superior hardness compared to many other substances.