Question

which best describes stellar equilibrium? a. the star produces fuel at the same rate it burns fuel. b. heat produced during fusion reactions in the core is transferred to the surface. c. the core contains equal amounts of hydrogen and helium. d. pressure caused by fusion reactions in the core is balanced by the gravity exerted by the suns mass.

Explanation:

Stellar equilibrium is when the outward - pressure from nuclear fusion reactions in a star's core (radiation pressure) is balanced by the inward - pull of gravity due to the star's mass. This is known as hydrostatic equilibrium. Option A is incorrect as stars do not produce fuel at the same rate they burn it. Option B only describes heat transfer and not equilibrium. Option C about equal amounts of hydrogen and helium in the core is not related to the concept of equilibrium.

Answer:

D. Pressure caused by fusion reactions in the core is balanced by the gravity exerted by the sun's mass.