The origin of elements

Universe > The history of our universe > The origin of elements 

The first atoms  were formed around three minutes after the Big-bang and were mainly Hydrogen and Helium. After the formation of the first stars the rest of the known natural elements (e.g. Carbon, Oxygen, Iron) are created either in the nuclei of stars or during supernova explosions through nuclear fission and fusion processes. These element are expelled back to the Universe either through the mass outflows of the stars or by the stellar explosion known as supernovae.

Connection to Big Idea about energy: All the elements lighter than iron are formed from hydrogen and helium by stellar nucleosynthesis. The process of synthesizing these elements is exothermic and is the energy source during the whole life of the star. The creation of heavier elements in supernova nucleosynthesis is an endothermic reaction – energy is absorbed – which triggers the supernova explosion.

Connection to Big Idea about forces: Stars are balancing acts between the inward force of gravity trying to pull the star’s material inwards, and the outwards push of pressure due to nucleosynthesis in the core. In the end of the stellar life, the fuel runs out, leaving gravity to overpower the outward pressure and causing a runaway collapse of the star.

Connection to Big Idea about particles: All natural elements are created either in the nuclei of stars or during supernova explosions through nuclear fission and fusion processes. All other structures of matter are built from this elements. 

Subjects related: Chemistry, Physics

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