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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.
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.
21 Νοε 2020 · It is by mass the most common element on Earth, forming much of Earth’s outer and inner core. It is the fourth most common element in the Earth’s crust. Its abundance in rocky planets like Earth is due to its abundant production by fusion in high-mass stars.
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 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.
Seven isotopes of helium are known: Liquid helium (He-4) exists in two forms: He-4I and He-4II, with a sharp transition point at 2.174K. He-4I (above this temperature) is a normal liquid, but He-4II (below it) is unlike any other known substance.
Name: Helium. Symbol: He. Atomic Number: 2. Atomic Mass: 4.002602 amu. Melting Point: -272.0 °C (1.15 K, -457.6 °F) Boiling Point: -268.6 °C (4.549994 K, -451.48 °F) Number of Protons/Electrons: 2. Number of Neutrons: 2. Classification: Noble Gas. Crystal Structure: Hexagonal. Density @ 293 K: 0.1785 g/cm 3. Color: colorless. Atomic Structure.
