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Saturday, 27 June 2015

Helium

French astronomer Pierre Jules César Janssen discovered helium on August 17, 1868, while analyzing the chromosphere of the sun during a total solar eclipse in Guntur, India.

Helium is the only element that was discovered in space before found on Earth.

Because helium was found in the Sun before it was found on Earth, its name comes from the Greek word for Sun, helios.

Helium is a finite resource on Earth and cannot be manufactured.

Although helium is the second most abundant element in the universe, most of it in the Earth's atmosphere bleeds off into space.

The US government has held a stockpile of 1 billion cubic meters of helium since 1925. This is due to post World War 1 fear that we may run out of helium in case of blimp warfare. The Federal Helium Program sells vast amounts of the gas to U.S. companies that use it in everything from party balloons to MRI machines.

Helium is one of lightest and least dense of all the elements. Its low density is what causes balloons filled with the gas to float, buoyed up by the denser surrounding air.

Helium is called a noble gas, because it does not regularly mix with other chemicals and form new compounds. It has the lowest boiling point of all the elements.  There are seven noble gases (the other six are Oganesson, Radon, Xenon, Krypton, Argon and Neon). Helium has the least density and it is the lightest of all the noble gases.

Because helium is easily compressed and non-toxic, it is used in specialized breathing mixtures of gases for very deep scuba diving, as a replacement for the nitrogen that makes up about 75 per cent of our air

When Helium is cooled to almost absolute zero (-460°F or -273°C), the lowest temperature possible, it becomes a superfluid with unusual properties: it flows against gravity and will start running up and over the lip of a glass container.

The largest single use of liquid helium is to cool the superconducting magnets in modern MRI scanners.

Liquefied helium

Today, the US alone produces 75 percent of the world's helium. Nearly half of that total, or roughly 30 percent of the world's helium supply, comes from the U.S. Federal Helium Reserve. That reserve is held in a huge natural underground reservoir near Amarillo, Texas called the Bush Dome.

At the heart of the Sun 600 million tonnes of hydrogen are converted into helium every second.

Helium.makes up around 45 percent of the mass of the sun.

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