The diagram illustrates radioactive decay.
What statement correctly identifies structures 1 and 2 in the diagram?
A. Structure 1 is an unstable atom that turns into structure 2, a new atom.
B. Structure 1 is a stable element that breaks down into structure 2, and unstable element
C. Structure 1 is a radioactive element that loses particles to create structure 2, a released energy
D. Structure 1 is a radioactive atom that decays into structure 2, half of the original unstable element
