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,
Nickel silver (Shadow model); these are far rarer than traditional lacquered brass saxophones. Student-level flutes and piccolos are also made of silver-plated nickel silver, although upper-level models are likely to use sterling silver. Nickel silver produes a bright and powerful sound quality; an additional benefit is that the metal is harder and has more corrosion resistance than brass. Because of its hardness, it is the most commonly used material for woodwind keys. Most clarinets, flutes, oboes and similar wind instruments have nickel silver keys, normally silver-plated. It is used to produce the tubes (called staples) onto which oboe reeds are tied. Many