Chemical Combination:
Two or more substances combined to form a single substance is called chemical combination
A +B -> AB
Example:
- 2mg + O2 → 2mgO
- NH3 + HCl → NH4Cl
Three laws of chemical combination
- Law of Conservation of Mass
- Law of Definite Proportions.
- Law of Multiple Proportions.
- Gay Lussac's Law of Gaseous Volumes.
- Avogadro's Law.
Chemical Decomposition:
Single substance splits into two or more substances is called chemical decomposition
AB -> A + B
Example:
- CaCO3 → CaO + CO2
- Pb(NO3)2 → 2PbO +O2 +NO2
Types of Chemical decomposition
- Thermal decomposition reaction.
- Electrolytic decomposition reaction.
- Photo decomposition reaction.