The Origin of The Heavier Elements

Hydrogen atoms first produced in the big bang would need additional protons and neutrons to become helium and lithium.

In a nucleus, the strong force holds protons and neutrons together, which overcomes and opposes the repulsion between protons.

Protons can also be combined with neutrons to form heavier nuclei in a process called nuclear fusion.

refers to the splitting of a heavy nucleus into lighter nuclei This reaction sustains nuclear power plants as well as some nuclear weapons.

this reaction sustains nuclear power plants as well as some nuclear weapons

a reaction through which light nuclei combine to form a heavier nucleus

this reaction produces less radioactive products and is thus safer than nuclear fission and can generate fewer amounts of nuclear waste that must be disposed of properly

Nucleosynthesis in stars.

Responsible for the formation of heavy elements.

The two key processes of stellar nucleosynthesis are nuclear fusion and neutron capture. 

Nuclei of different elements from boron to iron formed from nuclear fusion.

Nuclei heavier than iron emerged from neutron capture in conjunction with beta decay.

Nuclear fusion and neutron capture release and requires energy, respectively. 

Exothermic reactions that form helium

Burning phases form heavier nuclei.

These reactions release energy in the form of heat or light.

These reactions include the proton-proton chain reaction (p-p chain), hydrogen burning, and carbon-nitrogen-oxygen cycle (CNO Cycle).

Helium Burning

Carbon and Oxygen Burning

Silicon Burning