Why is uranium 235 better than 238?

As U-235 molecules are lighter than the U-238 molecules they move faster and have a slightly better chance of passing through the pores in the membrane. The UF6 which diffuses through the membrane is thus slightly enriched, while the gas which did not pass through is depleted in U-235.

Is U-235 or U-238 more radioactive?

In general, uranium-235 and uranium-234 pose a greater radiological health risk than uranium-238 because they have much shorter half-lives, decay more quickly, and are thus “more radioactive.” Because all uranium isotopes are primarily alpha emitters, they are only hazardous if ingested or inhaled.

What is the difference between uranium 235 and uranium-238?

The difference between the three isotopes is the number of neutrons present in the nucleus. U-238 has 4 more neutrons than U-234 and three more neutrons than U-235. U-238 is more stable thus being more abundant naturally. U-235 is used as fuel in nuclear reactors and/or weapons.

Why is uranium 235 A good source for a chain reaction compared to uranium-238?

Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists in nature as a primordial nuclide. Uranium-235 has a half-life of 703.8 million years.

Why do we use uranium 235 in nuclear reactors?

The isotope U-235 is important because under certain conditions it can readily be split, yielding a lot of energy. It is therefore said to be ‘fissile’ and we use the expression ‘nuclear fission’. Meanwhile, like all radioactive isotopes, they decay.

Why is uranium-235 radioactive?

This radioactive metal is unique in that one of its isotopes, uranium-235, is the only naturally occurring isotope capable of sustaining a nuclear fission reaction. Uranium is naturally radioactive: Its nucleus is unstable, so the element is in a constant state of decay, seeking a more stable arrangement.

Which of the following distinguishes isotope uranium-238 from the isotope uranium 235?

Uranium- 238 has a mass number of 238. Uranium-235 has a mass number of 235. So uranium-238 has more neutrons than uranium-235. But they are still both atoms of uranium because they have the same number of protons.

Is uranium-238 unstable?

All isotopes of uranium are unstable and radioactive, but uranium 238 and uranium 235 have half-lives which are sufficiently long to have allowed them to still be present in the Solar System and indeed on Earth.

Why is uranium-235 preferred?

Why Uranium-235 is the most commonly used isotope for nuclear fission in current use in nuclear power generation?

The isotope U-235 is important because under certain conditions it can readily be split, yielding a lot of energy. It is therefore said to be ‘fissile’ and we use the expression ‘nuclear fission’.