Question

1) Define radioactivity.
2) What are radioactive elements ?​

Answer 1

$\huge\underline\frak{\fbox{AnSwEr :-}}$

1) Radioactivity: The phenomenon in which the unstable nuclei spontaneously undergo disintegration and emit a nuclear particle and gamma radiation transforming to a different nuclide is called radioactivity.

2) The elements which undergo spontaneous nuclear changes emitting nuclear particles are called radioactive elements.

Answer 2

1. As its name implies, radioactivity is the act of emitting radiation spontaneously. This is done by an atomic nucleus that, for some reason, is unstable; it "wants" to give up some energy in order to shift to a more stable configuration.

2.Unstable forms emit ionizing radiation and are radioactive. There are some elements with no stable form that are always radioactive, such as uranium. Elements that emit ionizing radiation are called radionuclides. When it decays, a radionuclide transforms into a different atom - a decay product.Radioactivity is an atomic property caused by reactions taking place in the atomic nucleus, which in certain isotopes of a number of elements is unstable and disintegrates with the production of radiation and usually of an atom or atoms of other elements.