Why the alpha particle hitting nucleous is slow in nuclear fission
Answers
The absorption of slow neutrons can induce fission in particular nuclei, which are referred to as the fissile nuclei. Neutrons emitted from such fission can lead to a sustainable chain reaction. If neutrons are moving too fast, fission will not occur.
Uranium or plutonium isotopes are normally used as the fuel in nuclear reactors. Their atoms have relatively large nuclei that are easy to split, especially when hit by neutrons. The nuclear symbol for a neutron is _{0}^{1}\textrm{n}.
When a uranium-235 or plutonium-239 nucleus is hit by a neutron, _{0}^{1}\textrm{n} the following happens:
the nucleus splits into two smaller nuclei known as daughter nuclei, which are radioactive
two or three more neutrons are released
some energy is released in the form of kinetic energy of the particles produced
The equation can be written as
_{92}^{235}\textrm{U}+_{0}^{1}\textrm{n}\rightarrow_{56}^{144}\textrm{Ba}+_{36}^{89}\textrm{Kr}+{3}_{0}^{1}\textrm{n}+ {\text{energy}}
Chain reaction
The additional neutrons released may also hit other uranium or plutonium nuclei and cause them to split. Even more neutrons are then released, which in turn can split more nuclei.
This is called a chain reaction.