Question

Hundreds, even thousands of stars may be easily observed in the night sky. What process produces the light from the stars?

A.
gravitational waves, released by the high mass of stars
B.
nuclear fusion, in which atomic nuclei combine
C.
radioactive decay of heavy elements
D.
chemical combustion of hydrogen

Answer 1

B. nuclear fusion, in which atomic nuclei combine

Stars generate energy by fusing light nuclei (mainly hydrogen into helium) in their cores. The fusion releases huge amounts of energy (photons and other particles); the photons diffuse outward and escape as the starlight we see. Chemical combustion and radioactive decay cannot supply the required energy, and gravitational waves are not the primary light source.