posted by Amy .
What is the difference between natural uranium and enriched uranium?
Enriched U has more U235 mixed with the U238 than is found in nature. U235 is more prone to nuclear reactions (it likes to absorb neutrons, then spontaneously break into pieces, releasing energy). The process of enrichment is through a physical process (centrifuges, or diffusion columns) that separates the isotopes of natural uranium, and these are difficult and costly processes.