A chemical reaction is a process in which one or more substances change into new substances with different properties. In this process, the particles of the starting materials (reactants) are rearranged to form the end materials (products).
Key points about chemical reactions:
- The original substances are called reactants, and the new ones formed are called products.
- During a reaction, the chemical bonds in reactants are broken, and new bonds are formed to make products.
- The total number of atoms of each element remains the same, but their arrangement changes.
- Reactions are often accompanied by observable changes, such as release of heat or light, color change, gas formation, or the appearance of a solid (precipitate).
- Examples in daily life include rusting of iron, cooking food, burning fuel, and digestion in the body.
In simple words: A chemical reaction is the transformation of old substances into new ones with new properties.