Question

The process shown in this diagram contributed great amounts of heat to the young planet Earth and is best known as radioactive
A) decay.
B) fission.
C) fusion.
D) isotope.

Answer 1

The process shown in this diagram contributed great amounts of heat to the young planet Earth and is best known as radioactive decay. Decay is known to release large amounts of heat.

Answer 2

Hey there

I believe the correct answer is (A) 

(A) = Decay