What is the atomic number of Helium?

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lemjay | High School Teacher | (Level 3) Senior Educator

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To determine the atomic number of helium, let's refer to the periodic table of elements.

Take note that the chemical symbol of helium is He. And atomic number is the number of protons present in the nucleus of the atom's element. In the Periodic Table, the atomic number is located at the top of the element's symbol.

Therefore, the atomic number of Helium is 2.

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ssarfraz | Student, Professional | (Level 2) Honors

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Helium is a chemical element whose symbol is He.

A simple way to find out the atomic number of helium is through a periodic table.

A periodic table is a table consisting chemical elements mentioned by their atomic symbols and their atomic numbers plus atomic mass.

Follow the following steps to determine the atomic number of helium:-

  1. First of all you should be sure about the atomic symbol of the chemical element, eg helium (He)
  2. Secondly, get a periodic table, find He symbol.
  3. The atomic number is the number of protons present in the nucleus of an atom.
  4. Now in the periodic table, the number mentioned above the atomic symbol of the element is an atomic number.
  5. In helium, atomic number is 2
  6. When we add number of protons and neutrons, we get atomic mass, in helium's case 2+2=4. So the number mentioned below the atomic symbol is the atomic mass.

In short, Helium's atomic number is 2

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aishukul | Student, Grade 10 | (Level 3) Honors

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The atomic number is the number of protons in the element. Helium has 2 protons and therefore, the atomic number is 2. It is helpful to look at the periodic table of elements to find this. It is located at the top of each element's name. In this case, He stands for Helium. You can also find the mass number of Helium which is located at the bottom of the symbol. 

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ssandhu05 | Student, Undergraduate | (Level 2) Honors

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The atomic number for helium is 2. The way find this number is by looking at the periodic table, and it will be listed as the second one. The atomic number is determined by how many protons there are in the center (or nucleus) of the atom. The more protons, the higher the number and vis versa. Helium only has two protons in the center of each helium atom, so that is why it is put there.

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malkaam | Student, Undergraduate | (Level 1) Valedictorian

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Helium is a chemical element with symbol He and its atomic number appearing in the periodic table is 2.

 According to Wikipedia, the great online dictionary, and I quote:

"It is a colorless, odorless, tasteless gas, a non-toxic element which is inert and monatomic gas that heads the noble gas group in the periodic table. It’s boiling and melting oints are the lowest among the elements and it exists only as a gas except in extreme conditions."

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mmenon | Student, Grade 12 | (Level 3) eNoter

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When determining the atomic number or mass number of any element, one must refer to the periodic table. The atomic number of an element is "the atomic numberof a chemical element (also known as its proton number) is the number of protons found in the nucleus of an atom of that element number of protons."

The symbol for Helium is He (which can be found on the top right side of the periodic table). The number above He is the atomic number while the number below it is the mass of He. Thus, the atomic number of He (Helium) is 2.


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rachellopez | Student, Grade 12 | (Level 1) Valedictorian

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The atomic number of an element is the number of protons in its nucleus. The atomic number of helium can be found on the periodic table; it is the number written above the elements abbreviation. Helium's abbreviation is He and is the second element on the periodic table. Therefore, Helium's atomic number is 2. 

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saru1 | Student, Grade 11 | eNotes Newbie

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its a silly question because the atomic number of "He" (helium) is 2

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