Chapter 40, Problem 5A

a. Which isotope of uranium is most common?

b. Which isotope of uranium will fission?

To determine

The most common isotope of Uranium.

Answer to Problem 5A

The most common isotope of Uranium is Uranium-238.

Explanation of Solution

Introduction:

The isotope of an element is the form of the element in which the chemical properties are same but the configuration of nucleus is different. The atomic number of isotopes of element remains same but having different mass number.

The isotopes of uranium are Uranium-235 and Uranium-238. The amount of Uranioum-235 in the natural uranium ore is very low. It is only 0.7% of the ore.

The other isotope of the uranium is Uranium-238 and it is most abundant isotope of the uranium.

Conclusion:

Thus, the most common isotope of uranium is Uranium-238.

To determine

The isotope of uranium that undergoes the fission.

Answer to Problem 5A

The isotope of uranium that undergoes fission is Uranium-235.

Explanation of Solution

Introduction:

The process of disintegration of the nucleus of heavier atom due to strong electrical force is called the nuclear fission. The amount of energy produced in nuclear fission is very high.

The amount of the Uranium-238 is higher than Uranium-235. The neutrons available for fission of every atom of Uranium-238 atoms are very low due to its high amount. The amount of the Uranium-235 is very less. So, the adequate number of neutrons become available for the fission.

Conclusion:

Thus, the isotope of uranium that undergoes fission is Uranium-235.