Nano3 dinitrogen oxide, also known as laughing gas, is a sweet-tasting gas used in dentistry. when solid ammonium nitrate is heated, the products are gaseous water and gaseous dinitrogen oxide. write the balanced chemical equation for the reaction.

This is a decomposition reaction, where ammonium nitrate is heated and decomposed to gaseous water and dinitrogen oxide.
Formulas for reactants and products with states are as follows;
ammonium nitrate - NH₄NO₃ (s)
water - H₂O (g)
dinitrogen oxide - N₂O (g)
balanced reactions when the masses of both sides of the equation must be balanced 

Balanced chemical equation 
NH₄NO₃(s) ---> 2H₂O(g) + N₂O(g)