companydirectorylist.com  Global Business Directories and Company Directories
Search Business,Company,Industry :


Country Lists
USA Company Directories
Canada Business Lists
Australia Business Directories
France Company Lists
Italy Company Lists
Spain Company Directories
Switzerland Business Lists
Austria Company Directories
Belgium Business Directories
Hong Kong Company Lists
China Business Lists
Taiwan Company Lists
United Arab Emirates Company Directories


Industry Catalogs
USA Industry Directories














  • Helium - Wikipedia
    Helium (from Greek: ἥλιος, romanized: helios, lit 'sun') is a chemical element; it has symbol He and atomic number 2 It is a colorless, odorless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table
  • 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
  • Helium (He) - Periodic Table
    Helium (He) 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 It is located in group eighteen, period one and block s of the periodic table
  • Helium Facts - Atomic Number 2 or He - Science Notes and Projects
    Helium is a chemical element with the symbol He and atomic number 2 It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table
  • Helium | Definition, Properties, Uses, Facts | Britannica
    Ordinary air contains about 5 parts per million of helium, and Earth’s crust is only about 8 parts per billion The nucleus of every helium atom contains two protons, but, as is the case with all elements, isotopes of helium exist The known isotopes of helium contain from one to six neutrons, so their mass numbers range from three to eight
  • Atomic Number of Helium He
    Atomic Number of Helium is 2 Chemical symbol for Helium is He Number of protons in Helium is 2 Atomic weight of Helium is 4 002602 u or g mol Melting point of Helium is -272,2 °C and its the boiling point is -268,9 °C
  • Periodic Table of Elements: Los Alamos National Laboratory
    While helium normally has a 0 valence, it seems to have a weak tendency to combine with certain other elements Means of preparing helium difluoride have been studied, and species such as HeNe and the molecular ions He+ and He++ have been investigated
  • Chemical Symbol for Helium - He - Periodic Table of Elements
    Helium is a chemical element with atomic number 2 which means there are 2 protons and 2 electrons in the atomic structure The chemical symbol for Helium is He




Business Directories,Company Directories
Business Directories,Company Directories copyright ©2005-2012 
disclaimer