Question

Identify the correct statement about properties of interstitial compounds.

• A. Melting point of these compounds is lower than parent metal.
• B. Densities of these compounds are higher than parent metal.
• C. Chemical properties of interstitial compounds are different than parent metal.
• D. Metallic carbides are chemically inert.

Hint:

Interstitial compounds lock up the lattice structure, which drastically boosts hardness and melting points while making the overall material highly resistant to chemical attacks (inert)!

Answer 1

The Correct Option is D

Step 1: Recall interstitial compounds.
Small atoms like C or N sit in the gaps of a metal lattice. This locks the structure and changes its properties.

Step 2: Test the statements.
Their melting points are higher than the metal, not lower, and their chemistry stays similar to the metal. So those statements are wrong.

Step 3: Find the true one.
The filled gaps make them very hard and chemically inert, so metallic carbides being inert is correct.
\[ \boxed{\text{Metallic carbides are chemically inert, option 4}} \]