Answer the following question given this paragraph: 

Radioactivity involves the spontaneous emission of material and/or energy from the nucleus of an atom. The most common radioactive atoms have high atomic numbers and contain a large excess of neutrons. Some typical radioactive elements are technetium (atomic number 43), promethium (atomic number 61), and all elements atomic number 84 (polonium) and higher. There are four primary types of emission, either involving the release of a particle from the nucleus or the release of energy. In many instances, both energy and a particle are produced by the radioactive event.


Q: What term refers to the emission of material or energy from an atom's nucleus?

 Choices:

- smog

- microscopic

- stasis

- radioactivity

A:
radioactivity
