Chapter 40, Problem 8A

Why must uranium be enriched so that it contains a higher percentage of U-235 in order to sustain a chain reaction?

To determine

The reason of enriching the uranium in order to sustain a chain reaction.

Explanation of Solution

Introduction:

The disintegration of the nucleus of heavy atom by absorbing the energy of the neutron is called the nuclear fission. The nuclear fission produces the energy and neutron in fission.

The uranium exists in nature in two forms. The first one is U-235 and the other is U-238. The amount of U-235 in naturally occurring ore is very low than the amount of U-238. The amount of U-235 is only 0.7% in uranium ore.

The fission reaction occurs only in Uranium-235 and does not occurs in Uranium-238. So, uranium must enriched to initiate the chain reaction.

Conclusion:

Thus, the uranium must enriched to sustain chain reaction because the amount of U-235 is only 0.7% in the uranium ore.