Hi, can anyone please explain to me how sigma bond is actually formed? I don't really get why. I thought it is the overlapping of the p orbital directly between the bonding atoms. However I didn't get a mark for it in the exam. Do I need to say that sigma bond is the overlapping of the s orbitals directly next to the bonding atoms to form a single covalent bond? Also, someone mentioned the head on overlapping but I thought sigma bond is when the orbitals are next to the bonding atoms though. Thanks.