Consider the following statements about the physical and chemical characteristics of interstitial compounds and identify the correct statements

(A) They have high melting points.
(B) They are very hard.
(C) They retain metallic conductivity.
(D) They are chemically very reactive.

Choose the correct answer from the options given below:

(A), (B) and (C) only

The correct answer is Option (2) → (A), (B) and (C) only

Analysis of the Characteristics:

• (A) They have high melting points (Correct): Their melting points are higher than those of the pure parent metals.
• (B) They are very hard (Correct): The presence of small atoms in the voids restricts the movement of metal layers, making them extremely hard. Some borides even approach the hardness of diamond.
• (C) They retain metallic conductivity (Correct): The electronic structure of the metal is not fundamentally disrupted, so they continue to conduct electricity and heat like the original metal.
• (D) They are chemically very reactive (Incorrect): On the contrary, interstitial compounds are known for being chemically inert.