Everything except Hydrogen & Helium (and part of the Helium is also formed within stars).
Hydrogen and helium are thought to be formed during the Big Bang. We also know that helium is formed in stars during the process of stellar evolution. The other elements formed in stars during stellar evolution and end-of-life stellar events (like a supernova). It could be said that with the exception of hydrogen, all the elements formed in stars during one phase or another of the life of stars. This though minute quantities of some isotopes that are found in nature appear in the decay chains of other isotopes and were not themselves created in stars as described.
Chemical elements were formed by stellar nucleosynthesis.
As many other chemical elements uranium was formed by stellar nucleosynthesis.
Yes, a planet cannot become a star through stellar evolution. Stars are formed from collapsing clouds of gas and dust, while planets are formed from the leftover material in a star's protoplanetary disk.
The two most common elements found in nebulas are hydrogen and helium. These elements are the building blocks of stars and galaxies, and are formed during the process of stellar nucleosynthesis.
As heavier elements are formed by fusion in the core, a massive star will eventually exhaust its nuclear fuel and trigger a supernova explosion. This explosion will generate immense energy, leading to the production and dispersal of even more heavy elements into space.
Ionized hydrogen and helium are the most abundant chemical elements in nebulae.
Scientific evidence suggests that magnesium is formed during stellar nucleosynthesis, specifically in the core of massive stars through processes like fusion and neutron capture reactions. These stellar processes create heavier elements like magnesium from lighter elements such as hydrogen and helium.
Magnesium is primarily formed in stars during the late stages of stellar evolution, specifically during the core helium-burning phase in stars with masses around 0.8-2 times that of the Sun. It is produced through various nuclear fusion processes, such as the triple-alpha process and other alpha-capture reactions, leading to the synthesis of magnesium and other elements.
Chemical elements are formed in the Universe by stellar nucleosynthesis.
Hydrogen and helium are primarily formed inside stars through nuclear fusion processes. As stars age and go through various stages of stellar evolution, they can also produce heavier elements such as carbon, oxygen, and iron through fusion reactions in their cores.
Carbon is formed in stars through nuclear fusion processes during the later stages of stellar evolution. During these processes, helium nuclei are fused together to form carbon atoms. This occurs in stars with sufficient mass and temperature to initiate these nuclear reactions.