Transcript: Evolved massive stars have sufficient pressure and gravity that the temperatures in their cores can cause heavy element creation beyond carbon. Consider the progress of a set of stars; one of 4, one of 6, one of 8, one of 10, and one of 12 solar masses. In the 4 to 6 solar mass stars, in their helium rich cores carbon can be produced by the triple alpha process. In the 8 solar mass stars a set of reactions beyond carbon can continue because the temperatures are about 500 million Kelvin. Thus, carbon can form oxygen, neon, and even magnesium in a set of reactions that add helium nuclei to the carbon nucleus. In the heaviest stars, 10 to 12 solar masses, the temperatures exceed a billion degrees Kelvin, and reactions such as two carbon nuclei combining to make a magnesium nucleus, two oxygen nuclei combining to make a sulfur nucleus, and two silicon nuclei combining to make a nickel-56 nucleus, which rapidly decays to cobalt and then iron, can all occur. Iron is the end of the chain of heavy element production in massive evolved stars.