A star’s mass strongly affects its evolution. Main-sequence means sustained hydrogen fusion in the core. A Sun-like star later becomes a red giant, sheds gas and leaves a white dwarf. Many massive stars undergo core-collapse supernovae and leave neutron stars or black holes. These remnants are different objects, not three successive stages for every star. Safety: Paper only; no heat, flame, impact or nuclear-reaction model. Stop: Stop at qualitative stages and element links. No exact mass cutoffs, isotope equations or stellar-age calculation.

Materials: Paper; Pencil; Nine paper stage cards 1. Write six Sun-like stage cards: nebula—gas and dust; protostar—collapsing, heating material; main sequence—hydrogen fuses to helium in the core; red giant—expanded outer layers and later helium fusion; planetary nebula—shed outer gas; white dwarf—remaining compact core cooling. Arrange them in order with arrows. 2. Add a branch after the shared early stages labelled much greater initial mass. Write three extra cards: massive evolved star—later fusion makes progressively heavier nuclei towards iron; core-collapse supernova—explosion disperses enriched material; compact remnant—neutron star or black hole, depending on the star’s evolution and remnant mass. 3. Draw separate arrows from supernova to neutron star and black hole. These are alternative remnants in a simplified pathway, not successive stages or a universal prediction. 4. Add an element lane beneath the stages: main sequence hydrogen → helium; later helium fusion makes carbon and oxygen; later massive-star stages make heavier nuclei. Draw ejecta arrows from planetary-nebula gas and supernova material into a future gas cloud. 5. Write an explanation comparing the Sun-like and massive paths. State that a planetary nebula is gas shed by a star, not a place where planets are being born. Done: Complete six Sun-like stages, the massive branch, two alternative remnants and the element/ejecta lane. Proof: Keep map and comparison. Note supplied stage order or remnant choices. Stop: Stop at qualitative stages and element links. No exact mass cutoffs, isotope equations or stellar-age calculation.