Search results
Results from the WOW.Com Content Network
In physics, mirror nuclei are a pair of isobars of two different elements where the number of protons of isobar one (Z 1) equals the number of neutrons of isobar two (N 2) and the number of protons of isotope two (Z 2) equals the number of neutrons in isotope one (N 1); in short: Z 1 = N 2 and Z 2 = N 1.
Some of the major unsolved problems in physics are theoretical, meaning that existing theories seem incapable of explaining a certain observed phenomenon or experimental result. The others are experimental, meaning that there is a difficulty in creating an experiment to test a proposed theory or investigate a phenomenon in greater detail.
In contrast, the proton numbers for which there are no stable isotopes are 43, 61, and 83 or more (83, 90, 92, and perhaps 94 have primordial radionuclides). [3] This is related to nuclear magic numbers , the number of nucleons forming complete shells within the nucleus, e.g. 2, 8, 20, 28, 50, 82, and 126.
The even-longer half-life of 2.2 × 10 24 years of tellurium-128 was measured by a unique method of detecting its radiogenic daughter xenon-128 and is the longest known experimentally measured half-life. [5] Another notable example is the only naturally occurring isotope of bismuth, bismuth-209, which has been predicted to be unstable with a ...
), have two odd–even stable isotopes each. This makes a total of 30×1 + 9×2 = 48 stable odd–even isotopes. The lightest example of this type of nuclide is 1 1 H (protium) as zero is an even number while the heaviest example is 205 81 Tl. There are also five primordial long-lived radioactive odd–even isotopes, 87 37 Rb, [9] 115 49 In ...
Isotope shifts in atomic spectra are minute differences between the electronic energy levels of isotopes of the same element. They are the focus of a multitude of theoretical and experimental efforts due to their importance for atomic and nuclear physics.
A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy excited state levels (higher energy levels). ). "Metastable" describes nuclei whose excited states have half-lives 100 to 1000 times longer than the half-lives of the excited nuclear states that decay with a "prompt" half life (ordinarily on the order of 10
Main page; Contents; Current events; Random article; About Wikipedia; Contact us