The property that neon and argon most likely share is low or no reactivity.
The property that neon and argon most likely share is low or no reactivity. To determine this, we can look at the periodic table and understand how elements within the same group generally behave. Group 18 elements are known as the noble gases, and they are characterized by having a full outer shell of electrons. This makes them highly stable and unreactive. Neon and argon, being in Group 18, both have full outer electron shells, which means they have low or no reactivity. Therefore, low or no reactivity is the property they most likely share.