Melting point: 0.95 K (−272.20 °C, −457.96 °F) (at 2.5 MPa) Boiling point: 4.222 K (−268.928 °C, −452.070 °F) Density (at STP) 0.1786 g/L: when liquid (at m.p.) 0.145 g/cm 3 : when liquid (at b.p.) 0.125 g/cm 3 : Triple point: 2.177 K, 5.043 kPa : Critical point: 5.1953 K, 0.22746 MPa : Heat of fusion: 0.0138 kJ/mol Meer weergeven Helium (from Greek: ἥλιος, romanized: helios, lit. 'sun') is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group … Meer weergeven Helium has a valence of zero and is chemically unreactive under all normal conditions. It is an electrical insulator unless Meer weergeven While balloons are perhaps the best known use of helium, they are a minor part of all helium use. Helium is used for many purposes that require some of its unique properties, … Meer weergeven Scientific discoveries The first evidence of helium was observed on August 18, 1868, as a bright yellow line with a Meer weergeven Atom In quantum mechanics In the perspective of quantum mechanics, helium is the … Meer weergeven Natural abundance Although it is rare on Earth, helium is the second most abundant element in the known … Meer weergeven While chemically inert, helium contamination impairs the operation of microelectromechanical systems (MEMS) such that … Meer weergeven WebHelium has the lowest melting point of any element and its boiling point is close to absolute zero. Unlike any other element, helium does not solidify but remains a liquid down to absolute zero (0 K) under ordinary …
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WebThe melting point of helium is approximately equal to 0.95 Kelvin (or -272.20 degrees Celsius) when it is placed under a pressure of 2.5 MPa. Under standard conditions for temperature and pressure, the density of this element corresponds to 1.7186 grams per litre. WebAt 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). Its boiling point and critical point depend on which isotope of helium is … smart bone automatic \u0026 interactive dogs toy
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Web23 mei 2024 · Helium, at pressures below 25 atm and absolute zero, does not freeze because it's zero point energy is high enough to stop it from going into a solid phase, and hence is stable as a liquid. Other gases in general do not have such high zero point energies, and thus transition from liquid to metal as the temperature plunges. WebThis article contains comparison of key thermal and atomic properties of helium and neon, two comparable chemical elements from the periodic table. It also contains basic descriptions and applications of ... Melting Point-272.2 °C-248 °C: Boiling Point-268.9 °C-248.7 °C: Thermal Conductivity: 0.1513 W/mK: 0.0493 W/mK: Thermal Expansion ... Web20 jul. 1998 · The normal liquid form is called helium I and exists at temperatures from its boiling point of 4.21 K (−268.9 °C) down to about … hill rom golvo lift