The mass of the star.
its original mass when it formed
The factor that determines whether a neutron star or a black hole forms after a supernova explosion is the mass of the collapsing core of the star. If the core's mass is between about 1.4 and 3 times the mass of the sun, a neutron star is formed. If the core's mass exceeds about 3 solar masses, a black hole is likely to form.
No, black holes cannot turn into neutron stars. Neutron stars form from the remnants of supernova explosions of massive stars, while black holes are formed from the gravitational collapse of massive stars. Once a black hole is formed, it will remain a black hole and will not transform into a neutron star.
The black hole property that determines the Schwarzschild radius of the black hole is that it has mass but no angular momentum nor electric charge.
The Sun probably won't turn into a black hole. What determines whether a certain star becomes a black hole is basically the amount of mass left over, once the star runs out of energy. Less massive stars turn into white dwarves; more massive stars into neutron stars; and the most massive of all, into black holes.
A black hole or a neutron star.
A black hole has more mass than a neutron star, but if you are comparing volume it would depend on the mass of the black hole. A neutron star is estimated to be about 14 miles in diameter, which is larger than the event horizon of a black hole up to about 3.8 times the mass of the sun. A more massive black hole will be larger.
A neutron star or a pulsar, or a black hole.
When it turns into a black dwarf neutron star or black hole.
about 1/3 of a neutron star
after a neutron star collapses on itself
when a star dies