Final answer:
True, a star similar to the Sun spends most of its life as a main sequence star, fusing hydrogen into helium, before evolving into a red giant and eventually shedding mass to become a white dwarf when nuclear fusion ceases in its core.
Step-by-step explanation:
True, before turning into a white dwarf, a star like the Sun will spend most of its life as a main sequence star. During the main-sequence phase, a star like the Sun fuses hydrogen into helium in its core, providing the energy necessary to support itself against gravitational collapse.
When the hydrogen in the core is exhausted, the star evolves into a red giant, expanding significantly as it starts to fuse helium into heavier elements. Once the helium is depleted, the outer layers are expelled, creating a planetary nebula, and the core stabilizes due to degeneracy pressure. This pressure prevents further collapse, resulting in the formation of a white dwarf. A star's evolution from a main-sequence to a white dwarf sees vast changes in luminosity, temperature, and size, eventually leading to a cessation of nuclear fusion.
Mass loss is a key factor in a star's evolution to a white dwarf. For stars like the Sun, they are expected to shed around 45% of their initial mass and become white dwarfs with masses less than the Chandrasekhar limit, which is approximately 1.4 Msun.