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That’s where helium comes in: With a boiling point of minus 452 degrees Fahrenheit, liquid helium is the coldest element on Earth. Pumped inside an MRI magnet, helium lets the current travel ...
The world is running out of helium. Helium is the only element cold enough to keep MRI machines cool enough to function. Without it, doctors lose a valuable imaging tool.
Liquid helium is a physical state of helium at very low temperatures at standard atmospheric pressures.Liquid helium may show superfluidity.. At standard pressure, the chemical element helium exists in a liquid form only at the extremely low temperature of −269 °C (−452.20 °F; 4.15 K).
Helium is the least water-soluble monatomic gas, [96] and one of the least water-soluble of any gas (CF 4, SF 6, and C 4 F 8 have lower mole fraction solubilities: 0.3802, 0.4394, and 0.2372 x 2 /10 −5, respectively, versus helium's 0.70797 x 2 /10 −5), [97] and helium's index of refraction is closer to unity than that of any other gas. [98]
In reaction to depleting helium sources, the Helium Act of March 3, 1927 was established to prohibit the sale of helium to foreign countries and for non-governmental domestic use. [8] By 1937, a number of factors collided to move the United States government to revise its helium policy and create the Helium Act of September 1, 1937.
Each atom of helium-4 is a boson particle, by virtue of its integer spin. A helium-3 atom is a fermion particle; it can form bosons only by pairing with another particle like itself, which occurs at much lower temperatures. The discovery of superfluidity in helium-3 was the basis for the award of the 1996 Nobel Prize in Physics. [1]
The US fluid ounce is based on the US gallon, which in turn is based on the wine gallon of 231 cubic inches that was used in the United Kingdom prior to 1824. With the adoption of the international inch , the US fluid ounce became 1 ⁄ 128 gal × 231 in 3 /gal × (2.54 cm/in) 3 = 29.5735295625 mL exactly, or about 4% larger than the imperial unit.
Image credits: ninja_shadow_rider #7. War in Sudan. 50 million people in Sudan before it started, estimated 9 million people have been displaced and today 750 thousand are facing imminent starvation.