Final answer:
Hydrogen was the element that represented most of the atoms in the early Universe.
Step-by-step explanation:
The element that represented most of the atoms in the early Universe is hydrogen. During the initial stages of the Universe, hydrogen was the predominant element. It formed from the abundance of protons and neutrons that existed in the hot, dense conditions after the Big Bang.
As the Universe expanded and cooled, hydrogen atoms began to combine through nuclear fusion, forming helium. This fusion process released enormous amounts of energy and eventually led to the formation of stars.
Today, hydrogen remains the most abundant element in the Universe, making up about 75% of its elemental mass.
Learn more about Early Universe and the abundance of hydrogen