Final answer:
The composition of the solar nebula is reflected today in the Sun's composition, mainly consisting of hydrogen and helium, which matches our current understanding of the typical cosmic makeup.
Step-by-step explanation:
The composition of the solar nebula is significantly matched by that of our present-day solar system's Sun. The solar nebula was a rotating cloud of vapor and dust from which the solar system formed approximately 4.5 billion years ago. As it collapsed under its own gravity, the material moved toward the center, becoming denser and hotter, leading to the vaporization of most of the solid materials. What remained after the formation of the planetary system was a composition that mainly consisted of hydrogen and helium, similar to what we observe in the Sun today.
Through the work of Cecilia Payne-Gaposchkin, it was discovered that the composition of the Sun and other stars, dominated by hydrogen and helium, is much more typical of the cosmic makeup than the composition of Earth. The solar wind from the young Sun eventually dispersed the remaining lighter gases, ending the initial formation period of the solar system.