http://www.ck12.org Chapter 25. Nuclear Physics
Radioactive sources may even be inserted directly into the cancerous cells. Radiation is also used to kill bacteria on
food in the process known as food irradiation, thus increasing the shelf life of perishable items.
For more information on food irradiation follow the link below.
http://en.wikipedia.org/wiki/Food_irradiation
As a result of the study of radioactivity, physicists discovered a new conservation law.
The law of conservation of nucleon number: The total number of nucleons(A)in any reaction remains con-
stant.When a nucleon falls to a lower energy level in the nucleus, a high-energy electromagnetic pulse, called a
gamma ray(γ)is emittedA=constant.