What is the balanced equation for the chemical reaction #Mg_3N_2+2H_2O -> Mg(OH)_2+NH_3#?
Now, the first thing is to monitor each element as an individual and count the number of moles present in each on the left side and equate it to exactly the same number of moles to the same element on the right side.
For example, we have
On the left side, there are 3 moles of
And the question you ask yourself...is mass balanced, and is charge balanced...and so you count up the atoms on each side.... There are three metals atoms, 2 nitrogens, 12 hydrogens, and 6 oxygens ON BOTH SIDES of the equation....so the given reaction at least conforms to the principle of conservation of mass. It also conforms to experiment....