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Strontium is a chemical element; it has symbol Sr and atomic number 38. An alkaline earth metal , strontium is a soft silver-white yellowish metallic element that is highly chemically reactive . The metal forms a dark oxide layer when it is exposed to air.
The ratio 87 Sr/ 86 Sr is the parameter typically reported in geologic investigations; [4] ratios in minerals and rocks have values ranging from about 0.7 to greater than 4.0 (see rubidium–strontium dating). Because strontium has an electron configuration similar to that of calcium, it readily substitutes for calcium in minerals.
The only stable nuclides having an odd number of protons and an odd number of neutrons are hydrogen-2, lithium-6, boron-10, nitrogen-14 and (observationally) tantalum-180m. This is because the mass–energy of such atoms is usually higher than that of their neighbors on the same isobaric chain, so most of them are unstable to beta decay .
Hydrogen is the element with atomic number 1; helium, atomic number 2; lithium, atomic number 3; and so on. Each of these names can be further abbreviated by a one- or two-letter chemical symbol; those for hydrogen, helium, and lithium are respectively H, He, and Li. [6] Neutrons do not affect the atom's chemical identity, but do affect its weight.
Strontium-89 (89 Sr) is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 50.57 days. It undergoes β − decay into yttrium-89. Strontium-89 has an application in medicine. [2]
The kilonova briefly mimicked the conditions immediately following the Big Bang, and allowed scientists to confirm the source of the heavy elements Strontium and Yttrium for the very first time.
For each atom the subshells are given first in concise form, then with all subshells written out, followed by the number of electrons per shell. For phosphorus (element 15) as an example, the concise form is [Ne] 3s 2 3p 3.
These names are typically not used in the literature, and the elements are instead referred to by their atomic numbers; hence, element 164 is usually not called "unhexquadium" or "Uhq" (the systematic name and symbol), but rather "element 164" with symbol "164", "(164)", or "E164".