Nuclear Fusion10.3 - Understand the role of the Sun’s internal divisions in terms of energy production and transfer
10.4 - Understand the principal nuclear fusion process in the Sun (the proton-proton cycle)
The Sun consists primarily of the elements Hydrogen and Helium.
The Sun is large enough and contains enough mass that the internal pressure at its centre (its core) is so hot (14 million °C) that it forces the nuclei of the hydrogen atoms to join together (to fuse) to make helium atoms in a process called the proton-proton chain.
A nuclear reaction (fusion) takes place and large amounts of light and heat are produced. 600 million tonnes of hydrogen are converted into 596 million tonnes of helium every second. The remaining four million tonnes gets converted into heat and light.