Question

Which of the following noble gases is used in the treatment of cancer?
A. Xe
B. Ar
C. Rn
D. Kr

Answer 1

Hint: The noble gas which is used in the treatment of cancer is an element of period 6 and group 18. The atomic number of the element is 86 and is a p – block element.

Complete step by step answer:
The noble gas which is used in the treatment of cancer is Radon. The atomic number of Radon is 86 and is an element of the 6th period. It is a radioactive, odourless and tasteless noble gas. It is represented by Rn. It occurs naturally in minute quantities as an intermediate step in the normal radioactive decay chains through which thorium and uranium slowly decay into lead and various other short-lived radioactive elements. It is also the immediate decay product of radium. It is one of the rarest elements.
The most stable isotope of radium has a half-life of only 3.8 days. Under normal conditions, Radon is gaseous and easily inhaled. Radon gas is considered as a health hazard. Radon is one of the densest gases at room temperature and is the densest of the noble gases. Despite its short lifetime, radon gas from natural sources, such as uranium-containing minerals, can accumulate in buildings, especially, due to its high density, in low areas such as basements and crawl spaces. Radon can also occur in groundwater.

Hence, the correct answer is (C) Rn.

Note: Remember that Radon is the only noble gas used for the treatment of cancer, not the only element. Along with Radon, many other elements are also used to treat cancer.