Final answer:
Potassium, an alkali metal, is the most easily oxidized element on the given list due to its high reactivity and position at the top of the activity series. In contrast, gold and nitrogen are much less easily oxidized.
Step-by-step explanation:
When considering the oxidation tendencies of the elements listed, such as nitrogen, gold, potassium, and others, it's essential to reference the activity series and the concept of reduction potential. The activity series indicates that metals toward the bottom like gold are the most difficult to oxidize, while those toward the top, specifically the alkali and alkaline earth metals, are more easily oxidized.
Potassium, being an alkali metal, loses electrons very easily, reacting rapidly with oxygen to form metal oxides. Gold, in contrast, is found near the bottom of the series and hence is not readily oxidized. Nitrogen, being a nonmetal with a varied range of oxidation states, is also not easily oxidized, especially considering the stability of the dinitrogen (N₂) molecule. Metals like potassium can reduce nitrogen to form metal nitrides due to the high reactivity of potassium.
Based on the given list and understanding of these properties, potassium (j) would be the element that is most easily oxidized, while gold (e) and nitrogen (i) exhibit significantly lower tendencies to be oxidized.