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
Heart (symbol) but the "hearts" suit did not have this element since the 15th century. The heart symbol reached Japan with the Nanban trade of 1543 to 1614, as evidenced by an Edo period Samurai helmet (dated c. 1630), which includes both the rounded and indented forms of the heart symbol, representing the heart of Marishiten, goddess of archers. Since the 19th century, the symbol has often been used on Valentine's Day cards, candy boxes, and similar popular culture artifacts as a symbol of romantic love. The use of the heart symbol as a logograph for the English verb "to love" derives