Why do Uranium-235 Atoms split so easy...so too say...?

Question

and not some of the other elements...

Answer 1

Uranium is one of the heaviest elements in the Periodic Table. It's nucleus contains a very large number of protons and neutrons (atomic mass is around 235 as you indicated). What this implies is that Uranium's neucleus is unstable compared to other lighter elements. This instability has to do with the amount of binding energy that's required to keep the Uranium neucleus together. But a nucleus with so many protons with positive charges is also trying to push each other apart. So the neucleus is doing a balancing act with the strong force and eletromagnetic force.

In any case, a good analogy is to compare the Uraniam neucleus to a ball balanced on top of a slipery hill. Any moment if you tip the ball too much one way or the other, the ball will slide down the hill to the bottom. The uranium neucleus would prefer to split apart and find some other energy configuration that's lower in total energy. that's why Uranium is radioactive; it is constantly emitting photons (gamma rays), electrons (beta radiation), or small atomic nuclei (alpha radiation).

Answer 2

First of all is doesn't. Uranium 235 has a half life of 703,800,000 years, compared to Cs-137 (30.07 years) , Tc-99 (211,100 years), Cf-242 (3 min) etc that's pretty stable. It is because U-235 is relatively stable that we can use it in nuclear reactors.

In a reactor U-235 will absorb a neutron and become an excited U-236. This excitation in U-236 is due to the fact that the nucleons in U-236 are bound more tightly then in U-235 and in their reorganization some energy is freed. This energy is the binding energy of the last neutron. This freed energy can be emitted as a gamma ray or it can supply the nucleus with the energy required to fission.

When considering how easily an atom fissions you need to look at the critical energy needed to cause fission and the binding energy of the last neutron in the fissioning atom. For U-236 the binding energy (6.4 MeV) is greater than the critical energy (5.3 MeV) thus the act of U-235 absorbing a neutron alone releases enough energy to cause U-236 to fission. Lets now consider U-238 absorbing a neutron. The binding energy of the last neutron for U-239 is 4.9 MeV and the critical energy is 5.5 MeV thus, in addition to U-238 absorbing a neutron, you must some how add .6 MeV to the new U-239 atom before it can fission. Typically this energy is comes from the kinetic energy of the absorbed neutron. So only neutrons with .6 MeV or higher have a chance of causing U-238 to fission.

Answer 3

this might properly be a physics question, no longer biology it is likewise your homework... that's actual much less stressful and extra solid to examine the subject your self than ask the internet. To fuse is to convey 2 issues at the same time Fission is to interrupt some thing aside (As interior the notice fissure) Which do you think of occurs right here?

Answer 4

bcoz Uranium is radioactive substance and always cause chain reaction so they get split so easy

Answer 5

They are very unstable because of their size...