Question: Black holes are caused by stars exploding because they don't have enough fuel but how would they run out of their fuel?

Jose Eliel Camargo Molina answered on 15 Mar 2019:

Hi Jenn,

Think of it as two forces fighting each other. The gravity which is compressing the star very strongly, and the burning of fuel (kinda like nuclear explosions) that are trying to rip it apart.

If the fuel runs out because there are no nuclear reactions are possible, then gravity starts winning this fight and the star just gets so compressed that it becomes a black hole.