1. An addition reaction results in the conversion of one pi TT -bond and one sigma-bond into two sigma bonds SD Addition C-c X-Y X—c-c-Y 20- Bonds formed Bonds broken1. An addition reaction results in the conversion of one pi π -bond and one sigma-bond into two sigma bonds C C + X - Y X C C Y   Bonds broken 2  - Bonds formed sp 2 sp 3 Addition