Write the formula and valency of the Chromate ion.

• Chromate ion is the oxoanion formed when protons are removed from chromic acid.
• Chemical formula: Chromates have a chemical formula: ${{\mathrm{CrO}}_4}^{2-}$ and are often a bright yellow tint.
• Definition of valency: The amount of bonds that an atom may make as part of a compound is referred to as the element's valency. Valence electrons are electrons that are found in an atom's outermost shell.
• Valency of Cr in chromate ion: The oxidation state of chromate ion is $+6$, while the valency of chromate is $2$.

As a result, the chromate ion formula is ${{\mathrm{CrO}}_4}^{2-}$and the valency is $2$.