Among the given elements, W has the lowest ionization energy (12.0KJmol−1x10−3), indicating that it would be more likely to react with chlorine. X has a higher ionization energy ( 21.0KJmol−1×10−3 ), so it would be less reactive with chlorine compared to W . Based on ionization energy values, the elements that would react more readily with chlorine are W and X .