Not sure what your question is. I'm assuming you want to prove its accuracy?
The statement provided is accurate and demonstrates a good understanding of the composition and behavior of the Sun.
The Sun, like most stars, is made up primarily of hydrogen and helium. When the Sun formed approximately 4.6 billion years ago, it was composed almost entirely of hydrogen and helium, with small amounts of other elements.
As the Sun has aged, the process of fusion that occurs in its core has been consuming the hydrogen, converting it into helium. Despite this, the majority of the Sun's mass, approximately 74%, is still hydrogen. However, only a small fraction of this hydrogen is actually available for fusion in the core due to the Sun's internal structure.
The outer layers of the Sun, known as the photosphere and the chromosphere, are not hot enough for fusion to occur. It is only in the Sun's core, where the temperature is approximately 15 million degrees Celsius, that fusion occurs. Even then, only about 14% of the Sun's total hydrogen supply is able to participate in fusion due to the high pressure and density required for the process.
The remaining hydrogen remains in the Sun's outer layers, where it continues to exert gravitational pressure on the core region, helping to sustain the fusion reaction. Over time, as the Sun consumes more and more of its hydrogen supply, the core will continue to contract and heat up, ultimately leading to the transformation of the Sun into a red giant star.