What kind of material does the Big Bang theory say the universe is made of?
The Big Bang theory really does not directly predict anything about what kinds of material are in the universe. We need additional theories to explain why certain amounts of different materials are present. The Big Bang theory does say how the temperature and concentration of materials change, thus allowing us to conclude, for example, that the lightest chemical elements in the universe were made in nuclear fusion reactions when the universe was very hot and concentrated.
