Chemical reactions involve the transformation of substances into new substances with different properties through the rearrangement of atoms.

Chemical reactions occur when bonds between atoms are broken and new bonds are formed.

Chemical reactions are the basis for various natural and industrial processes.

They enable the production of new materials and substances.

Combustion of fuels such as gasoline, coal, or wood releasing energy in the form of heat and light.

Rusting of iron when exposed to air and moisture, resulting in the formation of iron oxide.

Chemical equations show the reactants and products involved in a chemical reaction.

Reactants are written on the left side of the equation, and products are written on the right side.

Balancing ensures that the number of atoms of each element is equal on both sides of the equation.

The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction, so the number of atoms must remain constant.

Combustion of methane: CH4 + 2O2 -> CO2 + 2H2O

Formation of water: 2H2 + O2 -> 2H2O

Occur when two or more substances combine to form a new compound.

General form: A + B -> AB

Example: 2Na + Cl2 -> 2NaCl

Occur when a compound breaks down into two or more simpler substances.

General form: AB -> A + B

Example: 2H2O -> 2H2 + O2

Take place when an element displaces another element from a compound.

General form: A + BC -> AC + B

Example: Zn + CuSO4 -> ZnSO4 + Cu

Involve the exchange of ions between two compounds, resulting in the formation of two new compounds.

General form: AB + CD -> AD + CB

Example: NaCl + AgNO3 -> AgCl + NaNO3

Increasing temperature generally increases the rate of reaction by providing more kinetic energy to the reacting particles.

Higher concentration of reactants leads to more collisions and faster reaction rates.

Catalysts are substances that speed up chemical reactions without being consumed in the process.

Greater surface area of solids leads to faster reactions as more particles are exposed to reactants.

Absorb heat energy from the surroundings, resulting in a decrease in temperature.

Example: Photosynthesis

Release heat energy to the surroundings, resulting in an increase in temperature.

Example: Combustion reactions