Basic Concepts
In a nutshell: Chemical reactions involve the transformation of substances and are essential to both industry and life.
## What Is a Chemical Reaction?
Chemical reactions happen when substances (reactants) interact to form new substances (products). Atoms are rearranged, but the total number of atoms is conserved.
### Types of Chemical Reactions
- **Synthesis:** Two or more substances combine to form one product.
- **Decomposition:** A compound breaks down into simpler substances.
- **Single Replacement:** An element replaces another in a compound.
- **Double Replacement:** Two compounds exchange elements.
## Reading and Writing Equations
Chemical reactions are represented by equations, showing reactants and products. Balancing equations ensures matter is conserved.
## Everyday Chemistry
Chemical reactions power everything from digesting food to running car engines and even fireworks!
Examples
- Burning methane: \( \mathrm{CH_4} + 2\,\mathrm{O_2} \rightarrow \mathrm{CO_2} + 2\,\mathrm{H_2O} \)
- Vinegar and baking soda reacting to produce carbon dioxide gas.
Key terms
- Reactant
- A starting substance in a chemical reaction.
- Product
- A substance formed as a result of a chemical reaction.
- Balanced Equation
- An equation with equal numbers of each atom on both sides.