What is a supernova?

Over its lifetime,the fusion reactions in the core of a massive star will produce not only helium,but also carbon, oxygen, nitrogen and all the other elements in the periodic table up to iron.But eventually, the core's fuel runs out,leaving it to collapse completely.That causes an unbelievably powerful explosion we call a supernova.Now there are two things to note about how supernovas create elements.First, this explosion releases so much energy that fusion goes wild forming elements with atoms even heavier than iron like silver, gold and uranium.