Answer:
Nitrogen atom
Step-by-step explanation:
- Oxidation and reduction in a equation can be shown using oxidation numbers.
- Oxidation number of Oxygen in KNO3 is -2 while in O2 is 0; this indicates reduction.
- Oxidation number of Nitrogen (N) in KNO3 is + 5, while in KNO2 is +3 , this indicates oxidation.
Hence;
- Nitrogen has undergone reduction while oxygen has undergone oxidation and therefore, nitrogen is the oxidizing agent and oxygen is the reducing agent.