Answer:
Decomposition and Synthesis
Step-by-step explanation:
The reaction of decomposition and synthesis are two of the important reaction. The decomposition reaction is usually defined as the reaction by which a bigger compound (molecule) is broken into smaller molecules. For example:
2KNO₃ ------> K₂O + N₂O + O₂
On the other hand, the synthesis reaction is defined as the reaction that accumulates smaller molecules and transforms into a larger compound (molecule). For example:
K₂O + N₂O + O₂ -------> 2KNO₃
Thus, the correct answers are options (B) and (D), i.e. Decomposition and Synthesis.