3-7 nuclear reactions: fission (11.2 pg 313-317)

3-7 Nuclear Reactions: Fission

(11.2 pg 313-317)

• The process of splitting a larger nucleus into smaller nuclei is called nuclear fission.

• Here is a ‘famous’ step-by-step example of fission from your text (please note the whole process is an example of artificial radioactivity):

– Uranium-236 is not stable, and splits into 2 nuclei

– We can write it like this:

• This process produces lots of extra energy (Fig.1 p.314), since a small amount of the mass is released as pure energy.

• The energy can be used to power electric turbines because (which is used to boil water make steam and turn the turbine). http://www.youtube.com/watch?v=VJfIbBDR3e8

• If you examine Table 1&2 p.315 (and maybe even read some of your textbook), you will see the ‘before and after’ of nuclear fission.

• Note the small amount of mass lost can produce a lot of power using Einstein’s equation (E=mc2).

• Nuclear fission can produce a lot of energy for ‘good’, but unfortunately can also be used to make a really powerful bomb.

• Only two nuclear bombs have ever been used in war, but had devastating consequences (Fig.2 p.316).

• They both were used on Japan at the end of World War II by Americans, and have never been used in a war since.

http://www.youtube.com/watch?v=fIbACkLU-38