What is Radioactivity? The phenomenon of spontaneous emission of radiations by an element or its compounds having peculiar characteristics similar to X-rays, i.e. affect a photographic plate even when wrapped in a black cloth or paper, cause ionization of gases through which they pass, penetrate through solids etc. is known as Radioactivity and the substances exhibiting the phenomenon of radioactivity are known as Radioactive Substances. Some substances which are not naturally radioactive but acquire radioactivity when exposed to radiations from a natural radioactive substance are known as Artificial radioactive substances and the phenomenon is known as Artificial or Induced Radioactivity. … Continue reading Radioactivity