Common noble gases are helium, xenon, neon, argon, and krypton. Each gas has its own unique uses, preparation methods and small stories of discovery.

Helium Gas:

Helium is a colorless, odorless, and non-explosive gas. Helium is so light that it weighs only one-seventh as much as air in its volume. It doesn't burn, so it replaces hydrogen in balloons and spacecraft. Industrial helium (98.2% purity) is liquefied to separate the rest of the gas at low temperatures and high pressures.

Neon Gas:

Neon gas is gaseous at standard atmospheric pressure, and although neon is the fifth most abundant element in the universe, it is rare on earth. Neon gas on Earth binds to the atmosphere and is extracted through a fractionation process. The main preparation method of neon gas is liquid air cooling separation.

Argon gas:

In early 1890, Lord Rayleigh and William Ramsay found the separated nitrogen from the air and from the ammonia nitrogen density difference, the experiments are very sophisticated operation, so the two of them doubt among them mixed with an unknown gas, and the Rayleigh also bold assumption that elements can be put into the back of the chlorine in the periodic table, as a result, in 1895, they according to the elements of experimental evidence and detail, call this element argon, argon gas. Argon does not naturally react with other compounds to form a solid, but can be "trapped" in radioactive rocks. Since argon is more readily available in the air, most industrial argon is extracted directly from the air. It is mainly extracted by fractional distillation.

Krypton Gas:

Krypton gas is a colorless, odorless, non-toxic, non-flammable, high-pressure gas stored in cylinders. The main preparation methods are air separation, ammonia tail gas extraction and solvent absorption of freon. Air separation is the most common method of separation. Krypton and xenon mixture are extracted from the air, and then impurities are removed to make pure krypton gas active.

Xenon Gas:

On July 12, 1898, after the discovery of krypton and neon, British chemists William Ramsay and Morris Travers discovered xenon in the residue left by vaporized liquid air. The rarity of xenon, a by-product of the process of separating nitrogen and oxygen from air, makes it much more expensive than other lighter gases, while the much higher stock of argon is cheaper.