1) energy is absorbed and bonds are broken
This is due to two reasons
1. The breaking of bonds requires and input energy. The formation of bonds is a release on energy. As bond breaking requires energy, it is only natural that once of the answers would involve the absorption of energy.
2. O2 is the covalent bond between two oxygen molecules. When these molecules are separated the bond is broken. As such the answer must be 1
I hope this helps
