Write any three properties of interstitial compounds.

Explanation

**Step-by-Step Solution:**

1. **Chemical Inertness**: Interstitial compounds are generally chemically inert. This means they do not readily react with other substances. Their structure, which involves small atoms occupying the interstitial spaces between larger metal atoms, contributes to their stability and resistance to chemical reactions.

2. **Hardness and Conductivity**: These compounds are typically hard and exhibit good conductivity of heat and electricity. The presence of small atoms in the interstitial sites enhances the metallic bonding, which results in increased hardness and allows for efficient conduction of heat and electrical current.

3. **High Melting Points**: Interstitial compounds have higher melting points compared to the pure metals from which they are formed. The strong bonding interactions due to the presence of smaller atoms in the lattice structure lead to greater stability and higher energy requirements to break these bonds during melting.

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