Answer : Option D) The particles move enough that they are not fixed in place, and the liquid can flow.
Explanation : The kinetic energy of the particles are allowed to move freely and are in motion when in the liquid state whereas the intermolecular particles can just flow; as the intermolecular attractions between the particles allows the liquid to flow by giving them a force to flow.
Ok, I see you have written the radioactive decay correctly, but what exactly is your question?
It tells us two expressions that mean the same thing/something that can represent the same thing.