Answer:
Oxygen and magnesium come together in a chemical reaction to form this compound. After it burns, it forms a white powder of the magnesium oxide. Magnesium gives up two electrons to oxygen atoms to form this powdery product. This is an exothermic reaction.
25
Explanation:
The coefficient 5 applis to each element in the molecule, so there are 5 times 1 H atom, 5 times 1 N atom, and ,since O has a 3 subscript, there are 5 times 3 O atoms. Therefore there are 25 atoms.