Chapter 40, Problem 4A

To determine

The reason for not occurring chain reaction in uranium ore.

Explanation of Solution

Introduction:

The chain reaction is the reaction in which neutrons produced in the one nuclear fission stimulates the nuclear fission of other atoms.

There exist many isotopes of an element in the nature. All the isotopes cannot undergo the nuclear fission. Only that isotope undergoes nuclear fission in which the electrical force predominates the strong nuclear force.

There are many isotopes of uranium. Not every isotope of uranium can undergo to nuclear fission. Only Uranium-235 undergoes the nuclear fission. The amount of Uranium-235 in the naturally occurring uranium ore is only 0.7%. This amount is very low.

The other isotope like Uranium-238 can only undergoes nuclear fission by absorbing the energy of external neutron. So, the chain reaction does not occur in the uranium ore.

Conclusion:

Thus, the uranium ore does not undergoes chain reaction because the amount of the uranium ore that can undergo chain reaction is very low.