1. Reactants: The starting materials in a chemical reaction are called reactants.
2. Breaking and Forming Bonds:
* Bonds break: The bonds between atoms within the reactant molecules break. This requires energy, often provided as heat, light, or electricity.
* Bonds form: New bonds form between different atoms, resulting in the formation of product molecules.
3. Products: The substances formed by a chemical reaction are called products. These products have a different chemical composition and structure compared to the reactants.
4. Energy Changes: Chemical reactions involve energy changes. Some reactions release energy (exothermic), while others require energy to proceed (endothermic).
Here are some key characteristics of chemical reactions:
* Chemical Change: The substances involved undergo a chemical change, meaning they transform into new substances with different properties.
* Conservation of Mass: The total mass of the reactants equals the total mass of the products. This is known as the Law of Conservation of Mass.
* Rearrangement of Atoms: Atoms are not created or destroyed during a reaction, but they are rearranged to form new molecules.
* Formation of New Bonds: New chemical bonds are formed between atoms.
Examples of chemical reactions:
* Burning wood: Wood (reactant) reacts with oxygen (reactant) to produce carbon dioxide, water, and ash (products). This reaction releases heat (exothermic).
* Baking a cake: The ingredients (reactants) undergo a chemical change when heated, resulting in the formation of a cake (product).
Understanding chemical reactions is crucial in many fields, including:
* Chemistry: The study of matter and its properties, including how substances interact and change.
* Biology: The study of living organisms, which rely on chemical reactions for growth, metabolism, and other processes.
* Medicine: Developing new drugs and treatments that involve chemical reactions in the body.
* Environmental Science: Understanding how chemical reactions affect the environment, such as pollution or climate change.
