- Several silicon Zintl ions ( Si 4 4 " Si 9 4 ", Si 5 2 " ) are known with group 1 counter ions.
- Prior to 1997, thomsonite was recognized as a mineral species, but a reclassification in 1997 by the International Mineralogical Association changed it to a series name, with the mineral species being named thomsonite-Ca and thomsonite-Sr . Thomsonite-Ca, by far the more common of the two is a hydrous sodium, calcium and aluminium silicate, NaCa 2 Al 5 Si 5 O 20 ?H 2 O . Strontium can substitute for the calcium and the appropriate species name depends on the dominant element.
- It's difficult to find si 5 in a sentence. 用si 5造句挺难的