Stellar Nucleosynthesis
Element Origins After the Big Bang, the ordinary matter in the Universe was composed primarily of just two elements: hydrogen and helium. Currently, there are a wide range of elements, from argon to zirconium. These more complex elements were nearly all produced via stellar evolution processes. The formation of new elements is called nucleosynthesis . Below, I have describe the basics of the chemistry of the Universe and how it has changed over time. Big Bang Nucleosynthesis The star-forming region 30 Doradus. The blue stars are massive, hot, young stars. They have formed in a cluster out of gas and dust. (Credit: NASA, ESA, HST WFC3) When the Big Bang occurred approximately 14 billion years ago, the Universe was very hot and dense. Over time, the Universe expanded and cooled down. Approximately 0.001 seconds after the Big Bang, particles (e.g., protons and neutrons) began to fuse together to form atomic nuclei, dubbed nuclear fusion . Nuclear fusion process
