Question

Arrange the following stars in order of their evolution: first select a star with no nuclear reactions.

a) Red giant, main sequence, white dwarf
b) Main sequence, red giant, supernova
c) Protostar, main sequence, black hole
d) Main sequence, supernova, neutron star

Answer 1

To arrange stars in order of their evolutionary stages, we should start with a protostar, followed by the main sequence, then the red giant phase, and end with the white dwarf stage. Thus, option c) Protostar, main sequence, red giant is the closest to the correct order.

Step-by-step explanation:

To arrange the given stages of a star's evolution in order, one should start with the phase where no nuclear reactions are taking place in the core. The evolutionary sequence for a star like our Sun would be:

1. Protostar: A contracting mass of gas that represents a very early stage of star formation, where nuclear reactions have not yet begun.
2. Main Sequence: A stable period in a star's life when it is fusing hydrogen into helium in its core.
3. Red Giant: A stage where the star expands and cools after it has exhausted the hydrogen in its core, and helium (and other elements, in some stars) fusion occurs in shells around the core.
4. White Dwarf: A compact, dense remnant left after a low-to-intermediate mass star has shed its outer layers and no longer has nuclear fusion occurring in its core.

Therefore, from the options provided, option c) Protostar, main sequence, red giant closely matches the correct order of star evolution phases, with the slight adjustment that a white dwarf stage would follow the red giant stage.