Once a massive star builds a massive Iron/Nickel core at the end of the Silicon Burning day, it is doomed. A catastrophic core collapse is followed by explosive ejection of the envelope in a Supernova. This lecture describes the stages of a core-bounce supernova explosion, and the subsequent seeding of the interstellar medium with heavy metals by the explosion debris. The fate of the collapsing core is the subject of the next lecture in this series. Recorded 2006 January 30 in 1008 Evans Laboratory on the Columbus campus of The Ohio State University.