Which element would most likely have a positive electron affinity?

na

al

rb

ar

I believe the correct answer from the choices listed above is the first option. The element that would most likely have a positive electron affinity would be sodium, Na. Electron affinity is defined as the change in energy of a neutral atom when an electron is added to the atom.

Both models are effective because they show the valence electrons, and these valence electrons indicate the reactivity of an element.