What is the term for the ability of an atom to emit, or give off, charged particles and energy from its nucleus?
conductivity
magnetism
electrical attraction
radioactivity
Radioactivity is the ability of an atom to emit, or give off, charged particles and energy from its nucleus. The charged particles and energy are called by the general term radiation . Only unstable nuclei emit radiation. They are unstable because they have too much energy, too many protons, or an unstable ratio of protons to neutrons. For example, all elements with more than 83 protons—such as uranium, radium, and polonium—have unstable nuclei. They are called radioactive elements. The nuclei of these elements must lose protons to become more stable. When they do, they become different elements.