Which element would be expected to have similar physical and chemical properties as oxygen, and why?

Sulfur because it has the same amount of valence electrons, sulfur forms two bonds in organic compounds, like oxygen. Both belong to chalcogen family, forms X^-2 ion, MX compound, and forms H2X compounds.

Alpha particles have positive charge, beta particles have negative charge, and answer 4 just doesn’t make sense. thus, you are left with only one possible answer.