Question

Uranium is a metallic element that is used in nuclear reactors and nuclear weapons. the vast majority of uranium found on earth is in the form of uranium-238, an isotope with a mass number of 238, while the uranium that is used for nuclear reactors and weapons is uranium-235, an isotope with a mass number of 235. what is the atomic difference between uranium-235 and uranium-238? uranium-235 has three fewer protons than uranium-238. uranium-235 has three fewer neutrons than uranium-238. uranium-235 has three fewer electrons than uranium-238. uranium-235 has three fewer atoms than uranium-238.

Answer 1

Hello!

the atomic difference between uranium-235 and uranium-238 is that uranium-235 has three fewer neutrons than uranium-238

Isotopes are atoms of the same elements which are only different in their amount of neutrons. That difference in the number of neutrons gives them different masses. Some isotopes are unstable, and they release neutrons (radiation) to transform into other, more stable, isotopes. When this happens the isotope is called a "radioactive isotope".  

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