The chromate ion is a polyatomic ion with the chemical formula CrO4^2-. It consists of one chromium atom bonded to four oxygen atoms, giving it a tetrahedral shape. Chromate ions are commonly found in various chemical compounds and are known for their bright yellow color. They are often used in industrial applications, such as in pigments and corrosion inhibitors. In aqueous solutions, chromate can exist in equilibrium with the dichromate ion (Cr2O7^2-) depending on the pH level. At higher pH levels, chromate is more stable, while at lower pH levels, dichromate predominates. Both forms are important in environmental chemistry, particularly in the context of heavy metal contamination and remediation efforts.