Helium - Wikipedia
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. [ 27 ] The vast majority of helium was formed by Big Bang nucleosynthesis one to three minutes after the Big Bang.
Helium - Element information, properties and uses | Periodic Table
Element Helium (He), Group 18, Atomic Number 2, s-block, Mass 4.003. Sources, facts, uses, scarcity (SRI), podcasts, alchemical symbols, videos and images.
Atomic Mass of all Elements (Chart + Rounded values)
Sep 1, 2024 · Access detailed info on all elements: atomic mass, electron configurations, charges, and more. View rotating Bohr models for all 118 elements. Get a free HD image of the Periodic Table.
Helium | Definition, Properties, Uses, & Facts | Britannica
Oct 25, 2024 · Helium constitutes about 23 percent of the mass of the universe and is thus second in abundance to hydrogen in the cosmos. Helium is concentrated in stars, where it is synthesized from hydrogen by nuclear fusion.
Helium (He) - Periodic Table
Helium is the 2nd element in the periodic table and has a symbol of He and atomic number of 2. It has an atomic weight of 4.00260 and a mass number of 4. Helium has two protons and two neutrons in its nucleus, and two electrons in one shell.
Helium - Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and tables showing density and specific weight of helium, He, at varying temperature and pressure - Imperial and SI Units.
Helium | He | CID 23987 - PubChem
Helium | He | CID 23987 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.
Helium - Periodic Table and Atomic Properties - Material …
Atomic mass of Helium is 4.0026 u. The atomic mass is the mass of an atom. The atomic mass or relative isotopic mass refers to the mass of a single particle, and therefore is tied to a certain specific isotope of an element.
helium - NIST Chemistry WebBook
Molecular weight: 4.002602. IUPAC Standard InChI: InChI=1S/He. IUPAC Standard InChIKey: SWQJXJOGLNCZEY-UHFFFAOYSA-N. CAS Registry Number: 7440-59-7. Chemical structure: This structure is also available as a 2d Mol file. Permanent link for this species. Use this link for bookmarking this species for future reference. Information on this page: Notes.
Atomic Data for Helium (He) - NIST
Notes: The spectroscopic data below are for the isotope 4 He. He I Ground State 1s 2 1 S 0 Ionization energy 198310.669 cm-1 (24.587387 eV) Ref. M02 He II Ground State 1s 2 S 1 / 2 Ionization energy 438908.8789 cm-1 (54.417760 eV) Ref. MK00b-1 (54.417760 eV) Ref. MK00b