Which element is most abundant in the universe?

Hydrogen is the most abundant element in the universe, making up about 74% of its elemental mass. This abundance is primarily due to hydrogen being the simplest and lightest element, consisting of just one proton and one electron. In the early universe, shortly after the Big Bang, hydrogen formed as the universe cooled and expanded, leading to its predominance over other elements. While helium is the second most abundant element, accounting for about 24% of the universe, hydrogen is distinctly more prevalent. The large proportion of hydrogen in stars, including our Sun, further illustrates its key role in cosmic processes, particularly in the formation of stars and the fusion reactions that power them.