Why Is Helium in Column 18

Helium atoms have two electrons in their outer shell and the other noble gases have eight electrons in their outer shell. This is the maximum number that will ‘fit’ each shell, making the atoms stable. … The noble gases are located in the far right column of the periodic table of elements – in group (column) 18.

Why does helium He only have 2 valence electrons?

Explanation: Helium is located in period 1, group 18 of the Periodic Table and has an atomic number equal to 2. As a result, neutral helium will only have 2 electrons surrounding its nucleus. … Two electrons in its outermost (and only) shell, two valence electrons.

How many valence electrons does the 18th column have?

Atoms of group 18 elements have eight valence electrons (or two in the case of helium). These elements already have a full outer energy level, so they are very stable. As a result, they rarely if ever react with other elements.