Which statement explains why neon is a Group 18 element?
(1) Neon is a gas at STP.(2) Neon has a low melting point.
(3) Neon atoms have a stable valence electron configuration.
(4) Neon atoms have two electrons in the first shell.
The answer is (3). Neon atoms have a stable valence electron configuration. This is a characteristic of Group 18 elements. This makes these elements not easy to react with other substances.