Lesson 25 – The Chemistry of Stars
In this lesson, we pause to examine the origins of the elements. With a newfound understanding for how biology uses elements to accomplish the chemistry of life, we examine the process that created those elements. Here we introduce the concept that dominates the universe, perhaps more than any other—gravitational collapse. This process fuses light elements into heavier ones in the hearts of stars through cycles of atomic fusion, including the CNO process and the proton-proton chain reaction. Depending on the type of star, different kinds of elements can be created, either during the star’s life, or when it explodes. Gravitational collapse is responsible for creating most of the elements on the periodic table, but also releases energy in the form of light as a star shines. We see that stars not only give the us the energy to power life processes, but also provide the atoms of life itself.