What is the most abundant element in the universe?

Hydrogen is recognized as the most abundant element in the universe, constituting about 75% of its elemental mass. This abundance can be traced back to the moments following the Big Bang, during which hydrogen was primarily formed. It is the simplest element, consisting of just one proton and one electron, and its abundance is further supported by its role in stellar processes.

In stars, hydrogen atoms undergo nuclear fusion to form helium, and this process releases a tremendous amount of energy, which sustains the stars and contributes to the overall composition of the universe. Given its central role in astrophysics, its lightweight nature, and its ability to form stars, hydrogen overwhelmingly outnumbers other elements in the universe. Thus, the choice of hydrogen aligns with established astronomical data and principles regarding elemental composition in our cosmos.