Answer the following question given this paragraph: 

When an atomic nucleus decays, it does so by releasing one or more particles. The atom often (but not always) turns into a different element during the decay process. The amount of radiation given off by a certain sample of radioactive material depends on the amount of material, how quickly it decays, and the nature of the decay product. Big, rapidly decaying samples are most dangerous.


Q: The atom often (but not always) turns into a different what during the decay process?

 Choices:

- concept

- reaction

- aspect

- element

A:
element
