Where and how was most of the helium in the universe created?
A)by nuclear reactions in the cores of stars, and was then thrown out into space by supernovae
B)by the collision of cosmic rays with hydrogen nuclei in interstellar gas clouds
C)by high-energy processes during the collapse of protogalactic clouds during the formation of galaxies
D)by nuclear reactions during the Big Bang

Question

Quizplus · Accepted Answer

Most of the helium in the universe was created during the Big Bang, which is supported by observations of the cosmic microwave background radiation. The Big Bang theory states that in the first few minutes after the Big Bang, the temperature and density were high enough for nuclear reactions to occur, forming helium-4 nuclei from protons and neutrons. This process is known as nucleosynthesis and is responsible for the creation of most of the helium in the universe.

Where and How Was Most of the Helium in the Universe