Question

Main sequence stars become these when they use up the hydrogen in their cores. They are huge because their outer layers expand *
A. main-sequence stars
B. protostars
C. red giants
D. nebula

Answer 1

Answer:

Main sequence stars fuse hydrogen atoms to form helium atoms in their cores. About 90 percent of the stars in the universe, including the sun, are main sequence stars. These stars can range from about a tenth of the mass of the sun to up to 200 times as massive.

Explanation:

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