When oxygen reacts with potassium, it undergoes a highly exothermic reaction to form potassium superoxide, KO2. This reaction is characterized by the transfer of electrons from potassium to oxygen, resulting in the formation of ionic species.

The chemical equation for this reaction is:

$$4K + O2 → 2K2O2$$

In this reaction, potassium atoms (K) lose one valence electron each, becoming positively charged potassium ions (K+). These potassium ions then combine with superoxide ions (O2-) to form potassium superoxide (K2O2).

The reaction between oxygen and potassium is highly vigorous and can be potentially hazardous. It releases a significant amount of heat and light, producing flames and sparks. Therefore, it is crucial to handle potassium and oxygen with extreme caution and under controlled conditions.