* Valency: Magnesium (Mg) has a valency of +2, meaning it can form two bonds. Bromine (Br) has a valency of -1, and Hydroxyl (OH) has a valency of -1.

* Bonding: In a stable compound, the positive and negative charges must balance. The given formula has a net charge of -1, indicating an imbalance.

A more likely compound containing these elements would be Magnesium bromide hydroxide (MgBrOH). This compound has the following structure:

* Mg is bonded to both Br and OH.

* The overall charge is neutral, with Mg having a +2 charge, Br having a -1 charge, and OH having a -1 charge.

Therefore, "Br-Mg-OH" is not a valid compound name.