Based only on the distance between the valence electron and the nucleus, which atom has a stronger attraction between its nucleus and its valence electrons? How do you know? Please explain in at least 2 sentences. lithium and sodium

Lithium

Explanation:

Although sodium may seem like a viable answer because it has more protons (and thus a greater attractive force) in its nucleus, we need to take into account what "valence electrons" means. Valence electrons are, simply, electrons that are on the outermost electron shell of an atom. Sodium has an additional shell of electrons compared to lithium that are far away from the nucleus. Thus, lithium, which has valence electrons closer to its nucleus, would have a stronger attraction between its nucleus and its valence electrons.