Why is helium an exception to the noble gases?

Answer 1

A Noble Gas does not need to have eight electrons to be classed as such - it simply must have a full outer shell. The first shell can only hold two electrons, which is what helium has, so helium is a Noble Gas. The second and third shells hold eight electrons, which is why other noble gases can be seen as having eight electrons. However no Noble Gases have eight electrons in total - just eight in the outer shell, as the shells fill from the inside out...

Answer 2

Helium is an exception to the noble gases because it has only two electrons in its outer shell, making it stable without forming chemical bonds. Other noble gases have full outer electron shells, which make them highly unreactive, but helium is the only one with a complete outer shell with just two electrons.

Answer 3

Helium is an exception to the rest of the noble gases because it has only two electrons in it's valence shell, unlike the rest which all have 8.

Answer 4

In the first shell - 1s - 2 electrons is also an extremely stable arrangement.

Answer 5

Unlike the other shells there is only room for 2 electrons in the first and smallest electron shell.

Answer 6

it's two two two and two