What is the formula for cobalt (II) iodide?

The chemical symbol for cobalt (II) iodide, or cobaltous iodide, is written as CoI2. Co is the chemical symbol for cobalt, and I is the chemical symbol for iodine.

The chemical symbol for each element is found on the periodic table of elements. This table also lists the atomic number and the atomic mass of each element, and it can be used to determine the charge and likely properties of different elements. The Roman numeral II after cobalt indicates that the cobalt ion contains a charge of plus two. The two after the I symbol indicates two atoms of iodine.