The hardest metal is tungsten. It is known for its remarkable hardness and high melting point, making it suitable for applications that require durability and strength. Tungsten's atomic number is 74, and it is often used in manufacturing high-performance tools, light bulb filaments, and electrical contacts, among other applications. Its density is higher than that of gold and lead, contributing to its status as one of the heaviest elements. Due to its unique properties, tungsten is also an essential material in the aerospace and military industries, where durability under extreme conditions is critical.