Nitrogen combines with metals to form Nitrides.

Explanation:
When nitrogen combines with metals, it forms compounds called nitrides. Nitrides are a class of chemical compounds in which nitrogen is combined with a metal. These compounds are formed by the direct reaction between nitrogen gas (N2) and the metal.

Formation of Nitrides:
The formation of nitrides occurs through a process called nitriding. Nitriding involves the reaction of nitrogen with a metal to form a nitride compound. This reaction can occur at high temperatures or under certain specific conditions.

Properties of Nitrides:
- Nitrides are generally hard and refractory compounds.
- They have high melting points and are often used in high-temperature applications.
- Nitrides exhibit a wide range of electrical and thermal conductivity properties, depending on the specific metal involved.
- Some nitrides are chemically inert, while others can react with water or acids.

Examples of Nitrides:
- Titanium nitride (TiN): It is a hard, ceramic material with a gold appearance. It is commonly used as a coating for metal surfaces to improve their hardness and wear resistance.
- Aluminum nitride (AlN): It is a semiconductor material with excellent thermal conductivity. It is used in electronic applications, such as high-power LEDs and microelectronic devices.
- Boron nitride (BN): It is a compound consisting of boron and nitrogen atoms. It has a similar structure to carbon graphite and has properties such as high thermal conductivity and electrical insulation.

Conclusion:
In summary, when nitrogen combines with metals, it forms compounds called nitrides. Nitrides have various properties and applications depending on the specific metal involved. Examples of nitrides include titanium nitride, aluminum nitride, and boron nitride.