Question

Which of the following is a radioactive element?
(A) Sulphur
(B) Polonium
(C) Tellurium
(D) Selenium

Answer 1

Hint: Some atomic nuclei contain excess nuclear charge that makes them unstable. These nuclei undergo radioactive decay to create stable nuclei. These substances are known as radioactive substances. The use of radioisotopes in diagnostic techniques in medicine is crucial. They can be used in combination with imaging tools that record the gamma rays emitted from within to image the dynamic processes occurring in various bodily areas.

Complete Step by Step Answer:
Among the given options, polonium is a radioactive element. The nucleus displays radioactivity as a result of nuclear instability. It is a phenomenon whereby heavier materials break down into comparably lighter ones through radiation emission. Polonium was discovered by Marie Curie in 1898. It has an atomic number of 84 and a mass number 209. It is a silver-coloured solid metal. Due to its radioactivity, this metal is highly toxic.
Correct Option: (B) Polonium.

Additional Information: A radioactive element can decay in three ways: alpha decay, beta decay, and gamma decay. Alpha decay is the name given to the nuclear disintegration process that produces alpha particles. An energetic electron that is released from the nucleus during this sort of decay is known as a beta particle. An electromagnetic energy (photon) packet known as a gamma ray is released by the nucleus of some radionuclides after radioactive decay.

Note: The concept of radioactivity was discovered by Henry Becquerel in 1896. A black paper-wrapped uranium compound was inserted into a drawer containing photographic plates. The plates were discovered to be exposed after a thorough analysis. Later on, this exposure gave rise to the idea of radioactive decay. Every radioactive element has a finite life.