The primary component of the sun's atmosphere is hydrogen, which constitutes about 74% of its mass. Helium follows as the second most abundant element, making up around 24%. The sun's atmosphere is structured in layers, including the photosphere, chromosphere, and corona. Hydrogen plays a crucial role in the process of nuclear fusion occurring at the sun's core, where it is converted into helium, releasing vast amounts of energy that powers the sun and emits light and heat. This fusion process is fundamental to the sun’s role as the central star of our solar system.