1. A heavy nucleus (U235 or Pu239), when bombarded by slow moving neutrons, split into two
or more nuclei.
2. Two or more neutrons are produced by fission of each nucleus.
3. Huge amount of energy is produced as a result of nuclear fission.
4. All the fission fragments are radioactive, giving off β and radiations.
<span>5. The atomic weights of fission products range from about </span>70 to 160.
6. The nuclear chain reactions can be controlled and maintained steadily by absorbing a
desired number of neutrons. This process is used in nuclear reactor.
<span>7. All the fission reactions are self-propagating chain-reactions because fission products contain </span>
neutrons (secondary neutrons) which further cause fission in other nuclei.
8. Every secondary neutron, released in the fission process, does not strike a nucleus, some
escape into air and hence a chain reaction cannot be maintained.
<span>9. The number of neutrons, resulting from a single fission, is known as the multiplication factor. </span>
When the multiplication factor is less than 1, a chain reaction does not take place.
<span>10. The control of chain reaction is necessary in order to maintain a steady reaction. This is </span>
carried out by absorbing a desired number of neutron by employing materials like
percentage of Cd, B or steel.
11. In a nuclear reactor, the multifactor is one. This is achieved by proper arrangement of
<span>fissionable materials.</span>
Norway
england
iceland
sweden
Estonia
latvia
ireland
france
switzerland
portugal
poland
germany
hungry
romana
Ukraine
belarus
austria
vatican city
belgiuiv
crotia
jersey
guernsey
isle of man
denmark
faroe island
san marinc
monace
united kingdom
greece
A. plate tectonics slowly move in what is called Continental Drift, the Earth used to be one continent called Pangea and has shifted ever since.
Trees are renewable resources because they can be replaced in a single lifetime and are replaced faster than they are harvested and used.
It can be maintained by responsible harvesting and use. One policy that many lumber companies advertise is that they plant a seed for every tree that they chop down.
Hope this helps! :)
