* Cation: A cation is a positively charged ion. It forms when an atom loses one or more electrons.
* Barium Ion (Ba²⁺): Barium loses two electrons to become a +2 ion, making it a cation.
* Chloride Ion (Cl⁻): Chlorine gains one electron to become a -1 ion, making it an anion.
* Nitrate Ion (NO₃⁻): Nitrate is a polyatomic ion (a group of atoms with a charge) that has a -1 charge, making it an anion.
* Chromate Ion (CrO₄²⁻): Chromate is another polyatomic ion with a -2 charge, making it an anion.
Therefore, the only cation in your list is the Barium Ion (Ba²⁺).
