What is the nature of most of the material at the core of the sun?

The core of the Sun primarily consists of hydrogen, which makes up about 74% of its mass, and helium, accounting for around 24%. Under the extreme temperature and pressure conditions, hydrogen undergoes nuclear fusion, converting into helium and releasing vast amounts of energy in the process. This fusion reaction is the source of the Sun's heat and light. Additionally, trace amounts of heavier elements like carbon, oxygen, and nitrogen are also present.