The energy from the sun that reaches earth is the result of which of the following processes, repeated many times in the core of the sun? A. The nuclei of two atoms are combined to form a single atom with larger nucleus.

B. Molecules are rearranged to form new substances with new properties.

C. Compounds are broken down into, smaller, less complex substances.

D. An atomic nucleus spontaneously splits into two separate atoms with less mass.