1. Elemental Composition of the Universe

2. The first 3 minutes…

3. Nucleosynthesis Nucleo  “having to do with nuclei”
Synthesis  “to make”
It is the creation of new atomic nuclei!
In astronomy, there are 2 types:
Big Bang nucleosynthesis
Stellar nucleosynthesis

4. BBN
Some scientists say that as the early universe expanded & cooled, quarks “froze” into protons and neutrons.
As it became too “cold” for other nuclear reactions to occur, unstable isotopes decayed
Most matter was then Hydrogen (a single proton), He-4, deuterium, He-3, and Li-7

6. Stellar nucleosynthesis
All other elements are the result of nuclear reactions in stars and supernova explosions.
As stars evolve, they convert H and He into the heavier elements.