Question

part 3: constructed response
12 based on the diagram, explain why massive stars live shorter lives than low - mass stars
13 describe the two possible outcomes after a supernova event
14 how is the evolutionary path of a sun - like star different from that of a massive star? use stages from the diagram in your answer.
15 why does the red dwarf path not lead to a supernova, even after hundreds of billions of years?
part 4: sequence practice
16 place the following in the correct order for a sun - like star: red giant, protostar, planetary nebula, white dwarf, star - forming nebula

Explanation:

1. Massive stars have more fuel but burn it at a much faster rate due to higher core temperatures and pressures caused by their greater mass. This rapid - burning depletes their fuel supply quicker, resulting in shorter lifetimes.
2. After a supernova event, two possible outcomes are: a neutron star can form if the remaining mass is between about 1.4 and 3 solar masses, where the core is compressed to extremely high densities with neutrons packed closely together. If the remaining mass is greater than about 3 solar masses, a black hole can form, a region with such strong gravitational pull that not even light can escape.
3. A Sun - like star starts as a star - forming nebula, becomes a protostar, then a main - sequence star. As it ages, it becomes a red giant, then sheds its outer layers to form a planetary nebula, and finally leaves behind a white dwarf. A massive star also starts as a star - forming nebula and protostar, but after the main - sequence stage, it becomes a red supergiant, undergoes a supernova explosion, and can end as a neutron star or black hole.
4. Red dwarfs have very low mass. They burn their fuel extremely slowly through a process called proton - proton chain reaction. Their cores never get hot or dense enough to trigger the advanced nuclear reactions that lead to a supernova. Even over long timescales, they lack the mass and internal conditions necessary for a supernova explosion.
5. Star - Forming Nebula, Protostar, Red Giant, Planetary Nebula, White Dwarf

Answer:

1. Massive stars burn fuel faster due to high mass - related conditions.
2. Neutron star (for 1.4 - 3 solar masses) or black hole (for > 3 solar masses).
3. Sun - like star: nebula - protostar - main - sequence - red giant - planetary nebula - white dwarf. Massive star: nebula - protostar - main - sequence - red supergiant - supernova - neutron star/black hole.
4. Low mass, slow fuel - burn, insufficient core conditions.
5. Star - Forming Nebula, Protostar, Red Giant, Planetary Nebula, White Dwarf