What is the sun's atmosphere comprised of?

The sun's atmosphere is primarily composed of three main layers: the photosphere, chromosphere, and corona. The photosphere, which is the visible surface, consists mainly of hydrogen and helium, along with trace amounts of other elements. Above this, the chromosphere contains hotter, ionized gases, while the corona, the outermost layer, extends far into space and is characterized by extremely high temperatures and a low density of particles, primarily consisting of ionized hydrogen and helium.