Nuclear Physics – Does Uranium-235 Always Split into Krypton and Barium in Fission?

nuclear-physics

In most nuclear fission examples and exercises, the products of a nuclear fission of Uranium-235 are two light nuclei of Krypton and Barium:

$$\mathrm{ _0^1n + U \longmapsto Kr + Ba + energy }$$

Is there some fission reaction that produces more stable nuclei instead of Krypton and Barium?

Please mention all possible fission equations of Uranium-235.
There's another question, is Uranium-235 the only fissile nucleus?

Best Answer

They don't. Here's a figure from Wikipedia:

distribution of fission product masses

Typically there's daughter with mass around 95, a daughter with mass around 140, and two or three extra free neutrons. In discussion of environmental contamination after nuclear accidents, you hear a lot about iodine-133 and strontium-90, because they are relatively long-lived and biologically active. Iodine-133 lives for about a week and accumulates in the thyroid; strontium-90 lives for about 30 years and can replace calcium in bones.

There are several heavy isotopes which can spontaneously fission; the big ones are uranium, plutonium, and californium.

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