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70 (1.939 × 10 18 kg) 2.55: 18.2: 2019: Preismonitor [20] [s] [al] 31: Ga: Gallium: 5.907: 19 (5.263 × 10 17 kg) 148: 872: 2019: Preismonitor [20] [s] [am] 32: Ge: Germanium: 5.323: 1.5 (4.155 × 10 16 kg) 914 – 1010: 4860 – 5390: 2020: SMM [39] [g] [an] 33: As: Arsenic: 5.776: 1.8 (4.986 × 10 16 kg) 0.999 – 1.31: 5.77 – 7.58: 2020 ...
The amount of mass that can be lifted by helium in air at sea level is: (1.292 - 0.178) kg/m 3 = 1.114 kg/m 3. and the buoyant force for one m 3 of helium in air at sea level is: 1 m 3 × 1.114 kg/m 3 × 9.8 N/kg= 10.9 N. Thus hydrogen's additional buoyancy compared to helium is: 11.8 / 10.9 ≈ 1.08, or approximately 8.0%
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]
Helium also has a very low boiling point (-268.9°C or -452°F), allowing it to remain a gas even in super-cold environments, an important feature because many rocket fuels are stored in that ...
[1] [3] [2] The amount of stored helium was very small before 1962 and the amount of available helium was essentially determined by the production of natural gas, from which it is separated as a side product, rather than by market forces. [2] [4] This situation changed in the early 1960s with the creation of the United States National Helium ...
An important property of helium-3, which distinguishes it from the more common helium-4, is that its nucleus is a fermion since it contains an odd number of spin 1 ⁄ 2 particles. Helium-4 nuclei are bosons, containing an even number of spin 1 ⁄ 2 particles. This is a direct result of the addition rules for quantized angular momentum.
In the Local Interstellar Cloud, the proportion of 3 He to 4 He is 1.62(29) × 10 −4, [6] which is ~121 times higher than in Earth's atmosphere. Rocks from Earth's crust have isotope ratios varying by as much as a factor of ten; this is used in geology to investigate the origin of rocks and the composition of the Earth's mantle . [ 7 ]