Question

Which of the following isotopes is used for treatment of cancer?
A. $C{o^{60}}$
B. ${K^{40}}$
C. $S{r^{90}}$
D. ${I^{131}}$

Answer 1

Isotopes are the different particles of the same element having the same number of protons but different number of neutrons. Isotope ${K^{40}}$ is the isotope of Potassium, isotope $S{r^{90}}$ is the isotope of Strontium, isotope ${I^{131}}$ is the isotope of Iodine and isotope $C{o^{60}}$ is the isotope of cobalt.

Complete answer:
Isotopes are the different particles of the same element having the same number of protons but different number of neutrons. As we know the proton number is the atomic number of the element. Therefore, the atomic number is the same for all isotopes of the same element. For example- carbon-12, carbon-13, and carbon-14 are the isotopes of the carbon with mass numbers 12, 13 and 14 respectively.

To answer this question, let us check the use of every isotope given in the options.Isotope ${K^{40}}$ is the isotope of Potassium. ${K^{40}}$ undergo beta decay and is primarily used as a banana equivalent dose. ${K^{40}}$is not used for treatment of cancer. Therefore, the option B is incorrect.

Isotope $S{r^{90}}$ is the isotope of Strontium. It is used as a radioactive tracer in medicine. Also, we can see the use of $S{r^{90}}$ in agricultural fields to study the crops. $S{r^{90}}$ is also used to treat eye diseases. Isotope ${K^{40}}$ is not used for the treatment of cancer. Therefore, the option C is incorrect.

Isotope ${I^{131}}$ is the isotope of Iodine. It is used for the treatment of thyroid. Isotope${I^{131}}$ is not used for the treatment of cancer. Therefore, the option D is incorrect.

We can see the use of isotope of cobalt, $C{o^{60}}$ in chemical reactions to trace the cobalt. Also, it is used in the sterilization process of medical equipment. One of the Isotopes of cobalt, $C{o^{60}}$ undergo gamma decay and is used to treat conditions like cancer. Therefore, the option A is correct.

So, the correct answer is option A.

Note: The isotopes which undergo gamma decay are generally used in the medicine. The gamma exposure can kill the cancer cells and be used to break down the tumor. Isotope ${I^{131}}$ is also used to cure thyroid for cancer and other abnormal conditions.