In a light water reactor ( LWR ), 79 % of 241 Am converts to 242 Am and 10 % to its nuclear isomer 242m Am:
32.
Another type of radioactive decay without change in mass number is emission of a gamma ray from a nuclear isomer or metastable excited state of an atomic nucleus.
33.
For a given nuclear isomer in two different physical or chemical environments ( different physical phases or different chemical combinations ) the electron wave functions are also different.
34.
The element also has 27 nuclear isomers, with masses of 141 154, 156, and 158 ( not every mass number corresponds to only one isomer ).
35.
Cells with colored borders ( note the three bottom cells in the color legend at right ) denote the half-life of the most stable nuclear isomer state.
36.
The most common gamma emitter used in medical applications is the nuclear isomer technetium-99m which emits gamma rays in the same energy range as diagnostic X-rays.
37.
The element also has 42 nuclear isomers, with masses of 150, 151, 153 162, 166 180 ( not every mass number corresponds to only one isomer ).
38.
Nuclear isomers owe their long half lives to the fact that their gamma decay is " forbidden " due to a large change in nuclear spin needed to emit a gamma.
39.
Phonons, nuclear isomers, even some upgraded version of the tin can telephone that contains ultrasound to use as a power source ( as has been proposed for refrigeration ).
40.
Whether a Nuclear isomer can qualify depends on our concept of time because the mysterious quantum mechanical uncertainty the Matter wave nature of fundamental particles forbids stable exact measurement of them.
