Allotropes of phosphorus Allotropes of phosphorus Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are also known. Gaseous phosphorus exists as diphosphorus and atomic phosphorus. White phosphorus, yellow phosphorus or simply tetraphosphorus (P) exists as molecules made up of four atoms in a tetrahedral structure. The tetrahedral arrangement results in ring strain and instability. The molecule is described as consisting of six single P–P bonds. Two different crystalline forms are known. The α form is defined as the standard state of the element, but is actually metastable under standard
Viola pedata typical garden environments because it does not tolerate rich, organic garden soils and excess moisture. Viola pedata Viola pedata, the birdsfoot violet, bird's-foot violet, or mountain pansy, is a violet native to sandy areas in central and eastern North America. Two primary color forms exist, "Viola pedata" var. "lineariloba" ("concolor"), which is a solid pink-lilac-lavendar color, and var. "pedata" ("bicolor"), in which the superior petals are a deep red-purple and the lateral and interior petals are similar to the concolor variety. Less common is "Viola pedata" var. "linearloba" forma "alba", which is a white flowered form. Birdsfoot violet favors well