The correct statement is:
Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
Helium, while being a noble gas like the other elements in group 18, has only 2 electrons, filling its first energy level and thus achieving a stable configuration. In contrast, the other noble gases (such as neon, argon, etc.) have 8 electrons in their outer energy level, which is characteristic of their stability.