Here's a breakdown:
* Rearrangement of atoms and molecules: Chemical reactions involve the breaking and forming of chemical bonds between atoms and molecules. This changes the way these atoms are connected, leading to different compounds.
* Formation of new substances: The rearrangement of atoms results in the formation of new substances with different chemical compositions and properties compared to the original reactants.
* Chemical properties: These properties include things like melting point, boiling point, reactivity, and color.
Key points:
* Chemical reactions are typically represented by chemical equations that show the reactants, products, and stoichiometric coefficients (the relative amounts of each substance involved).
* Chemical reactions can be endothermic (absorb energy) or exothermic (release energy).
* Catalysts can speed up chemical reactions without being consumed themselves.
Examples of chemical reactions:
* Combustion: Burning wood or fuel, where oxygen reacts with the fuel to produce carbon dioxide, water, and energy.
* Photosynthesis: Plants use sunlight, water, and carbon dioxide to produce glucose (sugar) and oxygen.
* Rusting: Iron reacting with oxygen and water to form iron oxide (rust).
* Baking a cake: Chemical reactions between ingredients like flour, sugar, and eggs create the final product.
In essence, chemical reactions are the building blocks of chemistry, driving the changes we see in the world around us.
