Responses
Helium atoms have valence electrons in the first energy level only, while atoms of the other elements in the group have valence electrons in the second energy level only.
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.
Helium atoms have 2 electrons, while atoms of the other elements in the group all have 18 electrons.
1 answer
The correct response is:
Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
This is the key difference, as helium has a complete outer shell with 2 electrons, whereas the other noble gases in Group 18 have 8 electrons in their outer shells.
