Number of isotopes (atoms of the same element with a different number of neutrons): 24; 5 stable Most common isotopes: Ca-40 (97 percent of natural abundance); Ca-44 (2 percent of natural abundance); Ca-42 (0.6 percent of natural abundance); Ca-48 (0.2 percent of natural abundance);...
Calcium, one of the alkaline earth metals, chemical symbol Ca, atomic number 20, the most abundant metallic element in the human body.
Absolute levels of total-body calcium can be determined by exposing a subject to a uniform neutron depth flux from 14-MeV neutrons produced by the 3H(d, n)4He reaction. The induced 49Ca can be measured with a whole-body counter with an invariant response to geometry and attenuation. This ...
Absolute levels of total-body calcium can be determined by exposing a subject to a uniform neutron depth flux from 14-MeV neutrons produced by the 3H(d, n)4He reaction. The induced 49Ca can be measured with a whole-body counter with an invariant response to geometry and attenuation. This ...
46Ca and 48Ca are the first "classically stable" nuclides with a six-neutron or eight-neutron excess respectively. Although extremely neutron-rich for such a light element, 48Ca is very stable because it is a doubly magic nucleus, having 20 protons and 28 neutrons arranged in closed shells....
ion channels and of imaging techniques to determine intracellular concentrations (activities) of calcium (4) and, more recently, of sodium and potassium in visually selected individual cells and/or microareas of cells, are as well suited to measure characteristics of glial cells as of neutrons.doi...
These are the heaviest isotopes of these elements ever found. Isotopes are different forms of elements found in nature. Isotopes of each element contain the same number of protons, but a different number of neutrons. The more neutrons that are added to an element, the "heavier" it is. The...
46Ca and 48Ca are the first "classically stable" nuclides with a six-neutron or eight-neutron excess respectively. Although extremely neutron-rich for such a light element, 48Ca is very stable because it is a doubly magic nucleus, having 20 protons and 28 neutrons arranged in closed shells....
Atomic Number:20 Atomic Mass:40.078 amu Melting Point:839.0 °C (1112.15 K, 1542.2 °F) Boiling Point:1484.0 °C (1757.15 K, 2703.2 °F) Number of Protons/Electrons:20 Number of Neutrons:20 Classification:Alkaline Earth Crystal Structure:Cubic ...
While the magic numbers N=2,8,20 are generally well understood, N=28 is the first standard magic number that is not reproduced in microscopic theories with two-nucleon forces. In this Letter, we show that three-nucleon forces give rise to repulsive interactions between two valence neutrons ...