Nucleosynthesis (noun, “NOO-kuh-lee-oh-SIN-this-is”)
Nucleosynthesis is a process by which new atomic nuclei are made. This process created all the elements that make up our universe.
Synthesis is a fancy word meaning to create something. So nucleosynthesis means nuclei are being created. In this case, the nuclei are inside atoms. That’s a big deal because an atom’s nucleus determines which element it is. By making new nuclei, nucleosynthesis makes different elements, too.
Nucleosynthesis works in one of two ways. It can start with protons and neutrons (or something even smaller) and bind them into a nucleus. Or it can start with a few lighter nuclei and fuse them into a heavier one.
This process doesn’t always change the element. If only the number of neutrons in a nucleus changes, the element stays the same. That’s because the number of protons, not neutrons, determines the element type.
Most nucleosynthesis occurs in the cosmos. It started with the Big Bang, which exploded our universe into being. As matter and space rapidly expanded from the Big Bang, particles started to group together. Some of those particles were protons and neutrons. And in joining them together, the Big Bang created atomic nuclei. Scientists believe that lighter elements, such as hydrogen and helium, came from nucleosynthesis during the Big Bang.
Other elements have been forged inside stars. During its lifetime, a star fuses lighter nuclei — such as hydrogen and helium — into heavier ones. The extreme gravity in the star’s core drives this process. This is called stellar nucleosynthesis. This is where much of the carbon, iron and other elements crucial for life originate.
Even in death, stars can form new elements. When supermassive stars die, they don’t just fade away. They explode as a supernova. This releases huge amounts of energy. Enough energy to fuse nuclei together and create new elements. Scientists believe supernova nucleosynthesis made much of the oxygen in our universe. Supernovas likely cooked up most of the elements heavier than iron, such as gold and uranium, too.
In a sentence
Scientists used lasers to mimic stellar core processes of nucleosynthesis.
