Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at 114 °C (237 °F), and boils to a violet gas at 184 °C (363 °F).
Symbol: I
Atomic mass: 126,90447 u
Atomic number: 53
Electron configuration: [Kr] 4d105s25p5
Period: period 5
Group: group 17 (halogens)
Melting point: (I2) 386.85 K (113.7 °C, 236.66 °F)