Information on Helium Gas
Created by radioactive decay and in the cores of stars, helium gas is a valuable commodity on Earth. Though used to float party balloons and Thanksgiving Day Parade characters, it also supercools MRI magnets and goes into gas mixtures for welding. Supplies of helium are limited on Earth; once used, it's difficult to recover. In 2009, with rising prices, careful management of this resource has been an important issue.
Other People Are Reading
-
Abundance
-
Though helium is abundant in the universe, it's rare on Earth. If it leaks into the air, it floats into space and disappears.
Formation
-
In stars, helium is created when hydrogen is compressed by large gravitational forces. On the Earth, it's formed slowly by natural radioactive decay in rocks deep in the crust. Pockets of helium become trapped in rock formations that sometimes also hold natural gas, so they can be found together.
-
Monatomic
-
Helium belongs to a family of elements called the Noble Gases. They don't react chemically or form molecules. This makes them valuable for many tasks, like welding.
Economics
-
The helium supply has been subject to demand pressures. Because the supply is limited, prices have gone up.
Density
-
Pure helium gas is less dense than air, so it can be used in balloons and blimps to make them float. Hydrogen has also been used for this, but its flammable nature makes it unsafe.
Low Temperatures
-
At normal pressures, helium will liquefy at cryogenic temperatures (4.2 Kelvins, or -269C), but never freeze solid.
-
