Search results
Results From The WOW.Com Content Network
Since the atmosphere of the Earth has a mass of about 5.14 × 10 18 kilograms (1.133 × 10 19 lb), [24] the mass of 3 He in the Earth's atmosphere is the product of these numbers, or about 37,000 tonnes (36,000 long tons; 41,000 short tons) of 3 He. (In fact the effective figure is ten times smaller, since the above ppm are ppmv and not ppmw.
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-2, 2 He, is extremely unstable. Its nucleus, a diproton, consists of two protons with no neutrons.According to theoretical calculations, it would be much more stable (but still β + decay to deuterium) if the strong force were 2% greater. [18]
The tonne (t) is an SI-compatible unit of mass equal to a megagram (Mg), or 10 3 kg. The unit is in common use for masses above about 10 3 kg and is often used with SI prefixes. For example, a gigagram ( Gg ) or 10 9 g is 10 3 tonnes, commonly called a kilotonne .
The interest stems from that accurate measurements of the unit cell volume, atomic weight and mass density of a pure crystalline solid provide a direct determination of the Avogadro constant. [3] The CODATA recommended value for the molar volume of silicon is 1.205 883 199 (60) × 10 −5 m 3 ⋅mol −1, with a relative standard uncertainty of ...
From January 2011 to December 2012, if you bought shares in companies when Randall J. Weisenburger joined the board, and sold them when he left, you would have a 43.7 percent return on your investment, compared to a 12.1 percent return from the S&P 500.
From January 2008 to December 2012, if you bought shares in companies when Reed E. Hundt joined the board, and sold them when he left, you would have a -21.5 percent return on your investment, compared to a -2.8 percent return from the S&P 500.
From June 2009 to December 2012, if you bought shares in companies when David L. Calhoun joined the board, and sold them when he left, you would have a 36.3 percent return on your investment, compared to a 51.9 percent return from the S&P 500.