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Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and ...
Calcium (20 Ca) has 26 known isotopes, ranging from 35 Ca to 60 Ca. There are five stable isotopes (40 Ca, 42 Ca, 43 Ca, 44 Ca and 46 Ca), plus one isotope (48 Ca) with such a long half-life that it is for all practical purposes stable. The most abundant isotope, 40 Ca, as well as the rare 46 Ca, are theoretically unstable on energetic grounds ...
When there is an excess of electrons, the object is said to be negatively charged. When there are fewer electrons than the number of protons in nuclei, the object is said to be positively charged. When the number of electrons and the number of protons are equal, their charges cancel each other and the object is said to be electrically neutral.
The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons [2] (e.g. K + (potassium ion)) while an anion is a negatively charged ion with more electrons than protons. [3] (e.g. Cl-(chloride ion) and OH-(hydroxide ion)).
Calcium in biology. Calcium is used in many nerves in the voltage-gated calcium channel which is slightly slower than the voltage-gated potassium channel. It is most notably used in the cardiac action potential. [1] Calcium ions (Ca 2+) contribute to the physiology and biochemistry of organisms' cells. They play an important role in signal ...
Contents. Electron configuration. In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals. [ 1 ] For example, the electron configuration of the neon atom is 1s2 2s2 2p6, meaning that the 1s, 2s, and 2p subshells are ...
Baryonic matter consists of quarks and particles made from quarks, like protons and neutrons. Free neutrons have a half-life of 613.9 seconds. Electrons and protons appear to be stable, to the best of current knowledge. (Theories of proton decay predict that the proton has a half life on the order of at least 10 32 years. To date, there is no ...
A proton is a stable subatomic particle, symbol. p. , H +, or 1 H + with a positive electric charge of +1 e (elementary charge). Its mass is slightly less than the mass of a neutron and approximately 1836 times the mass of an electron (the proton-to-electron mass ratio). Protons and neutrons, each with a mass of approximately one atomic mass ...