* Nickel(II) indicates the nickel ion has a +2 charge (Ni²⁺).
* Borate refers to the borate anion, which has a -1 charge (BO₂⁻).
To balance the charges, you need two borate anions (2 x -1 = -2) for every nickel(II) cation (+2). This leads to the formula Ni(BO₂)₂.
