Question

which process contributes to the formation of layers in protoplanets when unstable elements release particles and energy? compaction evaporation radioactive decay collision of space materials

Explanation:

Radioactive decay of unstable elements releases particles and energy. This energy can contribute to processes that lead to the formation of layers in protoplanets. Compaction is a mechanical process related to pressure - not directly related to energy release from unstable elements. Evaporation is a phase - change process not related to radioactive energy release in this context. Collision of space materials is a different mechanism from radioactive decay for energy release and layer formation in protoplanets.

Answer:

radioactive decay