Why do stars die?

Answer: Nuclear fuel depletes

Nuclear fuel depletes ✓ — Correct! Stars shine through nuclear fusion—hydrogen fusing to helium in cores. Eventually fuel exhausts. Low-mass stars (like sun): become red giants, shed outer layers (planetary nebulae), leave white dwarf cores. Massive stars (>8 solar masses): fuse heavier elements up to iron, then collapse explosively—supernovae—leaving neutron stars or black holes. Stellar death depends on mass!

Space friction slows them — Wrong. Space is nearly a vacuum—no friction. Stars die when nuclear fuel exhausts and can't support themselves against gravity.

Black holes consume them — Wrong. Some stars are consumed by black holes, but most die from fuel depletion—becoming white dwarfs, neutron stars, or black holes.