Simplify the following text for a Grade 8 native English-speaking person.
Original: Mercury ( I ) bromide is prepared by the oxidation of elemental mercury with elemental bromine or by adding sodium bromide to a solution of mercury ( I ) nitrate .
Simplified: It is made by reacting a bromide like potassium bromide or sodium bromide with mercury ( I ) nitrate . It can also be made by reacting mercury and bromine .