Chlorine, Cl
Chlorine is a halogen in group VII A of the periodic table with atomic number 17, an atomic weight of 35.45, and a density of 1.56 Mg/m3. In the solid state it forms a tretragonal crystal with a melting point of -101 C and a boiling point of -34.7 C.

The electronic configuration of Chlorine is (Ne)(3s2)(3p5). Its (-1) ionic radius is 0.181 nm.