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1 Σεπ 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.
Element Helium (He), Group 18, Atomic Number 2, s-block, Mass 4.003. Sources, facts, uses, scarcity (SRI), podcasts, alchemical symbols, videos and images.
A helium atom is an atom of the chemical element helium. Helium is composed of two electrons bound by the electromagnetic force to a nucleus containing two protons along with two neutrons, depending on the isotope, held together by the strong force.
26 Ιουν 2023 · The mass number (represented by the letter A) is defined as the total number of protons and neutrons in an atom. Consider the table below, which shows data from the first six elements of the periodic table.
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.
For elements with no stable isotopes, the mass number of the isotope with the longest half-life is in parentheses. Interactive periodic table showing names, electrons, and oxidation states. Visualize trends, 3D orbitals, isotopes, and mix compounds. Fully descriptive writeups.
