Classified as a noble gas, helium is a gas at 25°c (room temperature). Periodic table helium helium is a chemical element with symbol he and atomic number 2. Chemical symbol for helium is he.
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Helium is the lightest noble gas with two electrons filling the 1s state to close the first shell. Helium (he) helium is the 2nd element in the periodic table and has a symbol of he and atomic number of 2. Helium is a chemical element with the symbol he and atomic number 2.
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Defining the atomic number the atomic number for helium is 2. Atomic number of helium is 2. Helium is a chemical element of the periodic table with chemical symbol he and atomic number 2 with an atomic weight of 4.0026 u and is classed as a noble gas. Understanding this number is necessary for placing the element within the organization of the periodic table.
Seven isotopes of helium are known: Atomic weight of helium is 4.002602 u or g/mol. It has an atomic weight of 4.00260 and a mass number of 4. It has symbol he and atomic number 2.
Number of protons in helium is 2.
It is the second most abundant element in the universe, following hydrogen.
