## Chemistry: The Central Science (13th Edition)

$Mg (OH)_{2}$
Magnesium belongs to group 2, magnesium ion has a +2 charge ($Mg^{2+}$), Hydroxide ion has a -1 charge ($OH^{-}$). In order to balance, two hydroxide ions should be present. Thus, the formula will be $Mg (OH)_{2}$