$(\text{NH}_4)_2\text{Cr}_2\text{O}_7$ breaks down on heating. $(\text{NH}_4)_2\text{Cr}_2\text{O}_7 \rightarrow \text{N}_2 + 4\text{H}_2\text{O} + \text{Cr}_2\text{O}_3$ State which element undergoes oxidation and which element undergoes reduction?
- Aoxidised: chromium, reduced: nitrogen
- Boxidised: hydrogen, reduced: chromium
- Coxidised: nitrogen, reduced: chromium
- Doxidised: nitrogen, reduced: hydrogen