Question

These models show the electron structures of two different nonmetal elements.

Element 1 at left has a purple circle at center with 2 concentric black lines around it. The first line has 2 small green balls on it. The second line has 8 small green balls on it. Element 2 at right has a purple center with 5 concentric circles around it, with the first circle innermost. The first circle has 2 small green balls on it, and the second circle has 8 small green balls on it. The third circle has 18 small green balls on it, and the fourth circle has 18 small green balls on it. The fifth circle has 6 small green balls on it.

Which element is likely more reactive, and why?

Element 1 is more reactive because it has fewer electron shells and is toward the top of its group on the periodic table.
Element 1 is more reactive because it has more electrons in its valence shell and is farther to the right on the periodic table.
Element 2 is more reactive because it does not have a valence shell close to the nucleus, so it will attract electrons.
Element 2 is more reactive because it does not have a full valence shell, so it will attract electrons.
A B C OR D

Answer 1

D.

Element 1 has 2 shells with 2 and 8 electrons (total 10) — a noble gas (neon) with a full valence shell and is very unreactive. Element 2 has five shells ending in 6 valence electrons (total 52, tellurium); its outer shell is not full, so it tends to gain or share electrons and is more chemically reactive.