Chemical element named mendelevium in honor of D.I. Mendeleev, the first to arrange the elements in a periodic manner. Most recently, the synthesis of element 118 (since named oganesson) was reported in October 2006, and the synthesis of element 117 (tennessine) was reported in April 2010. Ten materials familiar to various prehistoric cultures are now known to be chemical elements: Carbon, copper, gold, iron, lead, mercury, silver, sulfur, tin, and zinc. Three additional materials now accepted as elements, arsenic, antimony, and bismuth, were recognized as distinct substances prior to 1500 AD. Phosphorus, cobalt, and platinum were isolated before 1750. Most of the
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