WebAtomic Weight: 4.00260. Classification: A noble gas and a nonmetal. Phase at Room Temperature: Gas. Density: 0.1786 g/L @ 0°C. Melting Point: -272.20°C, -457.96°F. Boiling Point: -268.93°C, -452.07°F. Discovered by: Pierre Janssen in 1868. Helium is the second lightest and second most common element in the universe. Web1 nov. 2024 · Helium and neon, the two lightest noble gases, have been traditionally positioned by IUPAC in the Group 18 of the Periodic Table of Elements, together with argon, and other unreactive or moderately reactive gaseous elements (krypton, xenon, radon), and oganesson.
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WebGaseous chemical element, symbol: He, atomic number: 2 and atomic weight 4,0026 g/mol. Helium is one of the noble gases of group O in the periodic table. It’s the second lightest element. The main helium source in the world is a series of fields of natural gas in the United States. Helium is a colourless, odourless, insipid and non-toxic gas. 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 in the periodic table. Its boiling point is the lowest among all the elements, and it does not … Meer weergeven Scientific discoveries The first evidence of helium was observed on August 18, 1868, as a bright yellow line with a wavelength of 587.49 nanometers in the spectrum of the chromosphere of the Sun. The line … Meer weergeven Natural abundance Although it is rare on Earth, helium is the second most abundant element in the known Universe, constituting 23% of its baryonic mass. Only hydrogen is more abundant. The vast majority of helium was formed by Meer weergeven While chemically inert, helium contamination impairs the operation of microelectromechanical systems (MEMS) such that iPhones may fail. Meer weergeven Atom In quantum mechanics In the perspective of quantum mechanics, helium is the … Meer weergeven Helium has a valence of zero and is chemically unreactive under all normal conditions. It is an electrical insulator unless ionized. As with the other noble gases, helium has metastable energy levels that allow it to remain ionized in an electrical … 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 … Meer weergeven Effects Neutral helium at standard conditions is non-toxic, plays no biological role and is found in … Meer weergeven adrian leggatt
Noble gas Definition, Elements, Properties, …
WebHelium. Molecular Formula He. Average mass 4.003 Da. Monoisotopic mass 4.002606 Da. ChemSpider ID 22423. WebHelium He CID 23987 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, ... Because the helium-4 atom … Webhelium-3. Molecular Formula 3He. Average mass 3.016 Da. Monoisotopic mass 3.016029 Da. ChemSpider ID 5256974. - Non-standard isotope. jt プルームテック+