The terrestrial planets are made almost entirely of elements heavier than hydrogen and helium. According to modern science, where did these elements come from?
A)They were produced by stars that lived and died before our solar system was born.
B)They have been present in the universe since its birth.
C)They were made by chemical reactions in interstellar gas.
D)They were produced by gravity in the solar nebula as it collapsed.

Question

Quizplus · Accepted Answer

Heavy elements are created in the hearts of stars through nuclear fusion reactions. When the star dies, it explodes in a supernova, scattering the heavy elements into space where they can potentially become part of new star systems, like our own solar system. This is known as the theory of nucleosynthesis.

The Terrestrial Planets Are Made Almost Entirely of Elements Heavier