Why are decomposition reactions called the opposite of combination reactions? Explain with equations of these reactions. (b) Express the following facts in the form of a balanced chemical equation: "When a strip of copper metal is placed in a solution of silver nitrate, metallic silver is precipitated and a solution containing copper nitrate is formed."

The reactions those split or break the compounds into two simpler products are called decomposition reaction

Example: decomposition of calcium carbonate into calcium oxide and carbon dioxide when heated CaCO3→ CaO + CO2

They are called opposite of combination reaction because in combination reaction two or more reactants combined to form one single product

Example Magnesium and oxygen combine to form magnesium dioxide 2Mg + O2→ 2MgO

(b) Cu (s) + 2AgNO3 (aq)→ Cu(NO3)2 (aq) + 2Ag (s)