Helium is in group 18 of the periodic table. How is helium different from the other elements in

Question

this group? (1 point)
Helium atoms have 2 electrons, while atoms of the other elements in the group all have 18
electrons.
Helium atoms have valence electrons in the first energy level, while atoms of the other elements
in the group have valence electrons in the second energy level.
Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have
8 valence electrons.
Helium atoms have a full outer energy level, while atoms of the other elements in the group do
not have a full outer energy level.

Answer 1

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.