What is the difference between natural and artificial radioactivity?

Natural radioactivity originates from naturally occurring radioactive substances, while artificial radioactivity is induced by human activities.

Natural radioactivity is a spontaneous process that occurs in certain elements, such as uranium, radon, and thorium. These elements have unstable nuclei that emit radiation in the form of alpha, beta, or gamma rays to achieve stability. This process is entirely natural and has been occurring since the formation of the Earth. The radiation emitted from these elements is present in our environment and contributes to the background radiation we are exposed to daily.

On the other hand, artificial radioactivity is a result of human activities. It is induced when stable nuclei are made unstable by bombarding them with high-energy particles in a nuclear reactor or a particle accelerator. This process does not occur naturally and was first observed by the French physicist Frederic Joliot-Curie and his wife Irene in 1934. The artificially radioactive substances produced in this way are used in various fields, including medicine for cancer treatment, in industry for thickness gauging, and in research for tracing chemical and biological processes.

IGCSE Physics Tutor Summary: Natural radioactivity happens by itself in elements like uranium, releasing radiation without human help. Artificial radioactivity, on the other hand, is created by humans using technology to make stable atoms unstable. Discovered in 1934 by Frederic Joliot-Curie and his wife Irene, artificial radioactivity is useful in medicine, industry, and science for various applications.