Sulfur is a yellow, nonmetallic element with an atomic number of 16 that was discovered by the ancients. It has a melting point of 112.8°C and boiling point of 444.6°C. While sulfur has no elasticity and a hardness of 1.5-2.5, it is harmful if inhaled, ingested, or through skin contact. It is found naturally in volcanic regions and salt domes near hot springs and is used to make products like fireworks, gunpowder, tires, and adhesives.