Which of these is true for a fission reaction? A. it is an endothermic reaction
B. a heavy nucleus splits into two smaller nuclei
C. two light nuclei combine to form a single heavier nucleus
D. it is an interaction between valence electrons of a atom.

How is energy related to the change of state represented by the model? atoms gain energy as a solid changes to a liquid. atoms gain energy as a solid changes to a gas. atoms lose energy as a solid changes to a liquid. atoms lose energy as a solid changes to a gas.