The first element formed in the universe was hydrogen. Shortly after the Big Bang, which occurred about 13.8 billion years ago, the universe began to cool and expand. During this cooling phase, protons and neutrons came together to form atomic nuclei in a process known as nucleosynthesis.
Hydrogen, which is the simplest and most abundant element, consists of just one proton and one electron. As the universe continued to cool, hydrogen atoms formed as protons captured electrons. Over time, some hydrogen atoms combined to create helium and trace amounts of other light elements through various nuclear reactions.
Understanding hydrogen’s role as the first element helps scientists piece together the history of the universe and the processes that led to the formation of stars and galaxies. This foundational element plays a crucial role in the cosmos, being the primary fuel for stars, including our own Sun.