Question

Which best describes a radioactive isotope?

(A) An atom is unstable.
(B)An atom is stable.
(C)There is only one other isotope.
(D)There are many isotopes

Answer 1

i think its A because the nuclei of some isotopes are unstable and emit radiation.

Answer 2

Answer: Option (A) is the correct answer.

Step-by-step explanation:

An isotope with an unstable nucleus which decomposes readily and results in the emission of radiation and a nuclear electron or helium nucleus achieves a stable nuclear composition is known as a radioactive isotope.

For example,
`^(210)_(84)Po \rightarrow ^(4)_(2)He + ^(206)_(82)Pb`

Here isotope of polonium decomposes in order to achieve a stable nuclear composition.

Thus, we can conclude that an atom is unstable best describes a radioactive isotope.