Final answer:
The reaction described in Document A is a double replacement reaction and demonstrates the Law of Conservation of Matter.
Step-by-step explanation:
The reaction described in Document A is a double replacement reaction. In a double replacement reaction, the cations and anions of two different compounds switch places to form new compounds. In this case, sodium bromide (NaBr) reacts with barium chloride (BaCl2) to form sodium chloride (NaCl) and barium bromide (BaBr2).
The chemical equation provided does demonstrate the Law of Conservation of Matter. The Law of Conservation of Matter states that matter cannot be created or destroyed in a chemical reaction, only rearranged. In this reaction, there are the same number and types of atoms on both sides of the equation, which means that matter is conserved.