The chemical formula for nickel iodide is NiI2. It can also be written as I2Ni. In the formula, the Ni indicates one atom of nickel and the I2 represents two atoms of iodine.
Nickel iodide is typically a solid that is black in color. It has a molecular weight of 312.50 grams per mole. Nickel iodide is often called nickel(II) iodide. The Roman numeral II indicates the two charge on the nickel ion that combines with the iodine to form nickel iodide. It may also be called diiodonickel or nickel diiodide. It is an inorganic compound commonly used for medicinal purposes.