Here's why:
* Electron Degeneracy Pressure: When a star like our Sun runs out of fuel, it sheds its outer layers, leaving behind a dense core. This core is so dense that electrons are forced to occupy the same energy levels, a phenomenon called electron degeneracy pressure.
* Electron Capture: The immense pressure in the core forces electrons to combine with protons, forming neutrons. This process, known as electron capture, releases a neutrino and reduces the number of protons in the core.
* Neutron Star or White Dwarf: The outcome depends on the initial mass of the star. If the core is massive enough, it collapses further, forming a neutron star. If it's less massive, the core stabilizes as a white dwarf, supported by the degeneracy pressure of the remaining electrons.
Therefore, while white dwarfs are composed primarily of carbon and oxygen, their formation involves the combination of electrons with protons.
