Innocent and Useful Gases in the Atmosphere

The Earth's atmosphere consists of 78% Nitrogen and 21% Oxygen. The remaining 1% contains several other gases, including six that are very useful and "innocent" (non-reactive). These are called Noble Gases: Helium, Neon, Argon, Krypton, Xenon, and Radon.

Characteristics of Noble Gases:

• They are not affected by the atmosphere and do not react chemically with other substances

• They are colorless and odorless

• They remain as gases and do not easily turn into liquid, even in extreme cold. They are usually separated in laboratories by cooling air until it liquefies.

Uses:

• Helium: Used in balloons.

• Neon and Argon: Used in colorful tube lights and lamps.

• Radon: Although toxic, it is used to detect water underground and to check iron welding.

• Krypton: Used in making fireproof windows, doors, and walls.

• Xenon: Used in high-intensity "arc lights" for bright illumination.