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Period: period 5: Block s-block ... Strontium is a chemical element; it has symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white ...
Strontium is the second element placed in the 5th period. It is an alkaline earth metal , a relatively reactive group, although not nearly as reactive as the alkali metals . Like rubidium, it has 5 electron shells or energy levels , and in accordance with the Madelung rule it has two electrons in its 5s subshell .
The superactinides may range from elements 121 through 157, which can be classified as the 5g and 6f elements of the eighth period, together with the first 7d element. [18] In the superactinide series, the 7d 3/2, 8p 1/2, 6f 5/2 and 5g 7/2 shells should all fill simultaneously. [16]
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
Each distinct atomic number therefore corresponds to a class of atom: these classes are called the chemical elements. [5] The chemical elements are what the periodic table classifies and organizes. Hydrogen is the element with atomic number 1; helium, atomic number 2; lithium, atomic number 3; and so on.
Strontium carbonate was discovered in minerals in the Scottish village of Strontian in 1790. The last element is the least abundant: radioactive radium, which was extracted from uraninite in 1898. [38] [39] [40] All elements except beryllium were isolated by electrolysis of molten compounds.
Group 5 is the new IUPAC name for this group; the old style name was group VB in the old US system (CAS) or group VA in the European system (old IUPAC). Group 5 must not be confused with the group with the old-style group crossed names of either VA (US system, CAS) or VB (European system, old IUPAC); that group is now called the pnictogens or ...
As of 1 Jan 2023, elements E119 and higher are not discovered. These are called theoretical elements. They can have article and other content pages though. Incidentally, this concerns period 8 completely. For the Infobox <element>, their redirected pages do not count (are treated as: "R page does not exist").