Seperate this redox reaction into its component half reactio

Seperate this redox reaction into its component half reactions( use the symbol e- for an electron)

3O2 + 4Cr ---> 2Cr2O3

Oxidation half reaction:

Reduction half reaction:

Please and thank you!

Solution

Oxidation half reaction: Cr ------------> Cr3+ + 3e- Reduction half reaction: O2 + 4e- ---------> 2 O2-