Enrichment of nuclear fuel 2 points A. increases the relative concentration of uranium-235 to 3-20% to produce energy in a power plant. B. increases the relative concentration of uranium-235 to 30-50% to avoid a nuclear explosion at higher percentages. C. increases the relative concentration of uranium-235 from 60% to 90% to achieve maximum electricity generation D. decreases the relative concentration of uranium-235 from 100% to 30-50% to avoid a nuclear explosion at higher percentages.

B. increases the relative concentration of uranium-235 to 30-50% to avoid a nuclear explosion at higher percentages.

Explanation:

Uranium enrichment may be defined as a process which is necessary for creating effective nuclear fuel from the mined uranium by mainly increasing the percentage of the uranium-235 that undergoes fission with a thermal neutrons.

The enrichment process removes the unwanted uranium-238, thus making uranium 235 concentration higher. It takes up much work to increase the relative concentration of the uranium 235 to make it 30% to 50% so as to avoid a nuclear explosion at such higher percentages.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.