Artificial radioactive elements are present in: A. s-block B. p-block C. d-block D. f-block
Hint: When an unstable atom’s nucleus loses energy by emitting radiation and alpha, beta particles and gamma rays then such process is called radioactivity. It is a natural process, but it is also found to be artificially induced. They are found in the extended part of the periodic table, i.e the part where Lanthanides and Actinides are found.
Complete answer: - Artificial radioactive elements are formed when an atom is found to be exposed to slow moving neutrons in a nuclear reactor. - Artificial radioactive elements are created by humans, these are actually artificial or we can say are unnatural. These are found in f- block, in the actinide series. - There are about 24 elements that are artificially made and don’t occur naturally on earth. - These can be called artificial, man-made or synthetic. - Few examples of these are: Plutonium, Neptunium, Uranium etc. - Artificial radioactive elements are with atomic numbers 95-118, in f-bock. -It is also found that the atoms of artificial radioactive elements now present on earth have formed are the product of experiments like nuclear fusion, nuclear reactors or we can say neutron absorption. - It is also found all these decay at a varying rate and all these are unstable. - Their half-lives are found to range from 15.6 million years to a few of hundreds of microseconds. - Hence, we can say that the correct option is (D), that is Artificial radioactive elements are present in f-block. So, the correct answer is “Option D”.
Note: - We can differentiate between natural and artificial radioactivity. Natural radioactivity is the emission of radiation from unstable nuclei. Whereas artificial radioactivity emission of radiation from naturally occurring isotopes that are bombarded with X-rays or gamma rays.