What is helium?
A: Helium is a chemical element with symbol He and atomic number 2.
It is a colorless, odorless, tasteless, non-toxic, inert,
monatomic what?
A: Gas that heads the noble gas group in the periodic table.
Its boiling and melting points are the what?
A: Lowest among the elements.
Helium exists only as a "what" except in extreme
conditions?
A: Gas.
Helium is the second "what" element?
A: Lightest.
It's the second most abundant element in what?
A: The observable universe, being present at about 24% of the total elemental
mass.
Most helium in the universe is helium-4, and is believed to
have been formed during what?
A: The Big Bang.
What is creating large amounts of new helium?
A: Nuclear fusion of hydrogen in stars.
Helium is named for what Greek god?
A: Helios, the sun God.
It was first detected as a what?
A: An unknown yellow spectral line signature in sunlight during a
solar eclipse
in 1868.
It was discovered by whom?
A: By French astronomer Jules Janssen.
In 1903, where were large reserves of helium found?
A: In natural gas fields in parts of the United States.
Helium is used in cryogenics for cooling what?
A: Superconducting magnets, with the main commercial application being in MRI
scanners.
Helium's other industrial uses account for how much of the
gas produced?
A: Half.
A well-known but minor use is as a lifting gas in what?
A: Balloons and airships.
As with any gas whose density differs from that of air,
inhaling a small volume of helium temporarily changes the timbre and quality of
what?
A: The human voice.
On Earth helium is relatively what?
A: Rare, 5.2 ppm by volume in the atmosphere.
In 1882, who detected helium on Earth, for the first time?
A: Italian physicist Luigi Palmieri.
On March 26, 1895, Scottish chemist Sir William Ramsay
isolated helium on Earth by doing what?
A: By treating the mineral cleveite with mineral acids.
Ramsay was looking for argon but, after separating nitrogen
and oxygen from the gas liberated by sulfuric acid, he noticed what?
A: A bright yellow line that matched the D3 line observed in the spectrum of the
Sun.
In 1907, Ernest Rutherford and Thomas Royds demonstrated
that alpha particles are what?
A: Helium nuclei.
In 1908, helium was first liquefied by whom by cooling the
gas to less than one kelvin?
A: Dutch physicist Heike Kamerlingh Onnes.
He tried to solidify it by further reducing the temperature
but why did he fail?
A: Because helium does not have a triple point temperature at which the solid,
liquid, and gas phases are at equilibrium.
Willem Hendrik Keesom was eventually able to solidify 1
cm3 of helium in 1926 by doing what?
A: Applying additional external pressure.
The US Navy sponsored three small experimental helium
plants during what?
A: World War I.
What was the goal of the three plants?
A: To supply barrage balloons with the non-flammable, lighter-than-air gas.
How much gas was produced?
A: A total of 5,700 m3 (200,000 cu ft) of 92% helium.
The government of the United States set up the what, in
1925 at Amarillo,
Texas?
A: National Helium Reserve.
What was the goal of the reserve?
A: Supplying military airships in time of
war and commercial airships in
peacetime.
Helium produced between 1930 and
1945 was how pure?
A: About 98.3% pure (2% nitrogen), which was adequate for airships.
In 1945, a small amount of 99.9% helium was produced for
what?
A: Welding use.
Commercial quantities of Grade A 99.95% helium were
available by what year?
A: By 1949.
For many years the United States produced how much of the commercially usable helium in the world?
A: Over 90%.
In the mid-1990s, a new plant in Arzew, Algeria began
operation, with enough production to cover what?
A: All of Europe's demand.
Meanwhile, by 2000, the consumption of helium within the
U.S. had risen to what?
A: Above 15 million kg per year.
As of 2012 the United States National Helium Reserve
accounted for how much of the world's helium?
A: 30 percent.
In the perspective of quantum mechanics, helium is the
second simplest atom to what?
A: Model, following the hydrogen atom.
Helium is composed of two electrons in atomic orbitals
surrounding a nucleus containing what?
A: Two protons along with some
neutrons.
The nucleus of the helium-4 atom is identical with a what?
A: An alpha particle.
