Period 6 element between barium and hafnium, and radium and rutherfordium, respectively. This convention is entirely a matter of aesthetics and formatting practicality; a rarely used wide-formatted periodic table inserts the lanthanide and actinide series in their proper places, as parts of the table's sixth and seventh rows (periods). Lanthanum is a chemical element with the symbol La and atomic number 57. It is the first element in the lanthanide series. It is a soft, ductile, silvery-white metal that tarnishes rapidly when exposed to air and is soft enough to be cut with a knife. It is the eponym of the lanthanide series,
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