how is it extracted?
For large-scale use, it is extracted by fractional distillation from natural gas, which can contain as much as 7% helium.
Helium
For large-scale use, helium is extracted by fractional distillation from natural gas, which can contain as much as 7% helium. 
what do the alternating bands of jupiter suggest the presence of The zones' lighter color is believed to result from ammonia ice; what gives the belts their darker colors is uncertain. what is it composed of? It is mostly made of molecular hydrogen and helium in roughly solar proportions. what can you tell me about its structure? The atmosphere is classified into four layers: the troposphere, stratosphere, thermosphere and exosphere; the planet does not have a solid surface, and the lowest atmospheric layer, the troposphere, smoothly transitions into the planet's fluid interior. what is the symbol of the second chemical component mentioned above? 'He' when was it initially discovered? 1868 where is it placed in the periodic table? It is  the first in the noble gas group in the periodic table. what is it used for? It is used as a breathing gas - helium mixtures such as trimix, heliox and heliair are used for deep diving to reduce the effects of narcosis, which worsen with increasing depth. where is it abundantly found? It is the second most abundant element in the known Universe, constituting 23% of its baryonic mass. does it cause any hazards? Inhaling helium can be dangerous if done to excess, since helium is a simple asphyxiant and so displaces oxygen needed for normal respiration.
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Helium [SEP] Modern extraction and distribution
For large-scale use, helium is extracted by fractional distillation from natural gas, which can contain as much as 7% helium. Since helium has a lower boiling point than any other element, low temperature and high pressure are used to liquefy nearly all the other gases (mostly nitrogen and methane). The resulting crude helium gas is purified by successive exposures to lowering temperatures, in which almost all of the remaining nitrogen and other gases are precipitated out of the gaseous mixture. Activated charcoal is used as a final purification step, usually resulting in 99.995% pure Grade-A helium. The principal impurity in Grade-A helium is neon.