Letter A1. Combination2. Decomposition3. Single replacement4. Double displacement5. DecompositionLetter BFor a chemical equation to be balanced, the number of atoms on both sides should be equal.1. Balanced2. Not balanced - [tex]\sf N_2+3H_2 \rightarrow 2NH_3[/tex]3. Balanced4. Not balanced - [tex]\sf 2NaOH + H_2SO_4 \rightarrow Na_2SO_4 + 2H_2O[/tex]5. Balanced