Final answer:
The result of a star's core collapse is either a white dwarf, neutron star, or black hole; the outcome depends on the core's mass. Low-mass stars become dense white dwarfs due to electron degeneracy pressure, whereas high-mass stars can form incredibly dense neutron stars or even black holes if the mass is sufficient.
Step-by-step explanation:
When the core of a star collapses while inside the star, the result is a white dwarf, a neutron star, or a black hole, depending on the mass of the core. For low-mass stars that cannot initiate further fusion, the core continues to shrink and its density skyrockets, reaching an extreme density where quantum physics comes into play. This leads to the formation of a white dwarf, which is incredibly dense and where electrons provide a degeneracy pressure that supports the star against further collapse.
In the case of a high-mass star, after collapsing rapidly under extreme gravity, the star becomes a neutron star or a black hole if the mass of the core exceeds approximately 3 Msun. If the collapse is halted at neutron degeneracy, a neutron star is formed, which has a density so high that if we were to replicate it, all the humans on Earth would be squeezed into the volume of a sugar cube. However, if no force can halt the collapse, the star's fate is sealed as a black hole.