Search results
Results From The WOW.Com Content Network
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.
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 a group of elements in the periodic table. Group 5 contains vanadium (V), niobium (Nb), tantalum (Ta) and dubnium (Db). [ 1 ] This group lies in the d-block of the periodic table.
They considered elements 158 through 164 to be homologues of groups 4 through 10, and not 6 through 12, noting similarities of electron configurations to the period 5 transition metals (e.g. element 159 7d 4 9s 1 vs Nb 4d 4 5s 1, element 160 7d 5 9s 1 vs Mo 4d 5 5s 1, element 162 7d 7 9s 1 vs Ru 4d 7 5s 1, element 163 7d 8 9s 1 vs Rh 4d 8 5s 1 ...
The radius increases sharply between the noble gas at the end of each period and the alkali metal at the beginning of the next period. These trends of the atomic radii (and of various other chemical and physical properties of the elements) can be explained by the electron shell theory of the atom; they provided important evidence for the ...
This table lists only the occurrences in compounds and complexes, not pure elements in their standard state or allotropes. Noble gas +1 Bold values are main oxidation states
In addition to the four stable isotopes, thirty-two unstable isotopes of strontium are known to exist, ranging from 73 Sr to 108 Sr. Radioactive isotopes of strontium primarily decay into the neighbouring elements yttrium (89 Sr and heavier isotopes, via beta minus decay) and rubidium (85 Sr, 83 Sr and lighter isotopes, via positron emission or ...