You are asked to determine whether a king's crown is really made of gold. You weigh the crown; it weighs 8 newtons in air and 7 newtons in water. Its volume is 0.0001 cubic meters. Given that the density of gold is 19,000 kilograms per cubic meter, the density of lead is 11,000 kilograms per cubic meter, and the density of iron is 8,000 kilograms per cubic meter, the king's crown is made of which material?