A decomposed reaction is a chemical reaction where a single reactant breaks down into two or more products. It's essentially the opposite of a combination reaction.

Here's a breakdown:

Definition: A decomposed reaction is a chemical reaction in which a single compound breaks down into two or more simpler substances.

General Form:

AB → A + B

* AB represents the single reactant (compound)

* A and B represent the products (simpler substances)

Types of Decomposition Reactions:

* Thermal Decomposition: Heat is used to break down the reactant. For example, heating calcium carbonate (CaCO₃) decomposes it into calcium oxide (CaO) and carbon dioxide (CO₂):

CaCO₃ (s) → CaO (s) + CO₂ (g)

* Electrolytic Decomposition: Electricity is used to break down the reactant. For example, electrolysis of water (H₂O) decomposes it into hydrogen gas (H₂) and oxygen gas (O₂):

2H₂O (l) → 2H₂ (g) + O₂ (g)

* Photodecomposition: Light energy is used to break down the reactant. For example, the decomposition of silver chloride (AgCl) into silver (Ag) and chlorine (Cl₂) when exposed to light:

2AgCl (s) → 2Ag (s) + Cl₂ (g)

Key Points:

* Decomposition reactions are endothermic, meaning they require energy input (usually heat, electricity, or light) to occur.

* The products of a decomposition reaction are often in a different state of matter than the reactant.

* Decomposition reactions are important in various fields, such as:

* Chemistry: Studying chemical bonds and reaction mechanisms

* Industry: Production of various chemicals and materials

* Nature: Breakdown of organic matter and formation of new compounds

Examples of Decomposition Reactions:

* The decomposition of hydrogen peroxide (H₂O₂) into water (H₂O) and oxygen (O₂)

* The decomposition of limestone (CaCO₃) into lime (CaO) and carbon dioxide (CO₂)

* The decomposition of potassium chlorate (KClO₃) into potassium chloride (KCl) and oxygen (O₂)

Let me know if you would like a more detailed explanation of any specific decomposition reaction!