Sulfur has been known for its medicinal value and its germicidal effect since prehistoric times. However, its chemical nature remained unknown until 1787 when Lavoisier recognized it is an element. Sulfur is the second member of group 6A in the periodic table.
Sulfur is a yellow solid in crystal or powder form. Sulfur is a non-metal and a poor conductor of heat and electricity. It is about two times denser than water (2.07 g/cm3). Sulfur is insoluble in water but soluble in CS2. Its melting point is 119.3°C and boiling point is 444.8°C. There are three common allotropes of sulfur: rhombic, monoclinic and plastic sulfur.