* In the 1930's nuclear energy became a serious possibility. * 1932 - Discovery of the neutron. * No change, ergo, can probe nucleus. * Hahn and Strassmann fired neutrons at U nucleus. * Lise Meitner and Otto Frisch interpreted this: Neutrons caused splitting of U into smaller nuclei * Fission had occurred. * Potent source of energy! * Energy from E=mc2 * In more complete form, Einstein showed that at relativistic speeds we cannot use k=(0.5)mv2 . * Remember from special relativity, that as …showed first 75 words of 366 total…

…showed last 75 words of 366 total…of protons). (iii) When they are close enough, the nuclear strong force pulls the protons together. Neutrons assist in binding. (iv) Potential energy decreases. Amount = binding energy. (v) This means mass decreases. * Peak binding energy about mass number = 60. (Fe to Cu). Most stable. * Energy released by fusion up to about A=60. Energy input above that. * Energy released by fission from top end down to 60. Canadian Reactor Technology AECL designed the CANDU reactor (Canada Deuterium Uranium)