The conversation between human and AI assistant.
What are the most abundant elements in the universe?
Why are these elements so abundant in the Universe?
Hydrogen is the most abundant element because it is the simplest and lightest element in the universe, and was also the first element formed after the Big Bang. Helium is also abundant since it was also formed during the Big Bang and is continuously produced by the nuclear fusion of hydrogen in stars. And oxygen, though less abundant than hydrogen and helium, is still relatively common in the universe due to its formation in the cores of massive stars and during supernova explosions.