What Is a Cul Ionic Compound?

One use for copper iodide is
••• Hemera Technologies/Photos.com/Getty Images

CuI is the elemental symbol abbreviation for the ionic chemical compound copper (I) iodide, also known as cuprous iodide. CuI is a solid formed from a mixture of the metallic element copper and the halogen iodine. It has various applications in chemistry and industry.

Ionic Compounds

An ionic compound forms when an atom of one element donates one or more electrons to an atom of a different element. The first atom becomes positively charged and the second becomes negatively charged. The two atoms now stick together due to the electrostatic attraction between their opposite charges. This is known as an ionic bond. Sodium chloride, or table salt, is a well-known ionic compound.

About CuI

CuI is an ionic compound that has each molecule made from one atom of copper (Cu) and one atom of iodine (I). The copper atom is positively charged and the iodine is negatively charged, so there is an ionic bond between them. It is written in full as copper (I) iodide to show that the copper has an oxidation state of 1, which means it has given up one electron.


CuI is a white crystalline powder with a density of 5.7 grams per cubic centimeter. It melts at 606 degrees C. It is essentially insoluble in water, which is unusual for an ionic compound. It is found naturally as the mineral marshite but can also be synthesized chemically.


CuI is an ingredient in various synthetic chemical reactions. It is also added to nylon to increase resistance to heat and light and has been used to produce a test paper to show the presence of mercury vapor. CuI has been used to "seed" clouds to produce rain.

Related Articles

Chemical Reactions That Cause Color Change
What is Ethanolic Potassium Hydroxide?
What Is the Gas Used in Neon Signs that Produces a...
What Is the Metallic Ion in the Compound CuCl2?
Elements Found in Household Products
Why is Quinine Fluorescent?
What Is Disodium Diphosphate?
Industrial Uses of Iodine
The Common Uses for Tartaric Acid
How to Make a Sodium Silicate Solution
What Is Zinc Alloy?
How to Make Sodium Nitrate
Where Is the Mineral Topaz Found?
Uses of Alkaline Earth Metals
The Effects of Oxidation on Copper
What Are the Colors of Neon?
Alternative Solvents to Benzene
How to Dissolve Polyethylene
What Types of Alloys Are Used in Jewelry?
Science Projects Using Borax