Overview
This topic explores the behavior of elements and compounds, focusing on how substances interact in chemical reactions. You'll learn about the structure of molecules, types of chemical bonds, balancing equations, and the conditions under which reactions occur.
Key Concepts in Chemistry
- Elements and Compounds: Elements consist of one type of atom. Compounds are substances formed from two or more elements chemically bonded together.
- Molecules: Two or more atoms bonded together, such as O2 or H2O.
- Chemical Bonds: Includes ionic (transfer of electrons), covalent (sharing of electrons), and metallic bonds.
- Chemical Reactions: Processes where substances (reactants) are transformed into new substances (products). Represented with chemical equations.
- Balancing Equations: Ensures that the number of atoms of each element is the same on both sides of the reaction equation.
- Types of Reactions: Synthesis, decomposition, single replacement, double replacement, combustion, and acid-base reactions.
- Law of Conservation of Mass: Matter is neither created nor destroyed in a chemical reaction; mass is conserved.
- Reaction Rates: Influenced by temperature, concentration, surface area, and catalysts.
- Acids and Bases: Acids release H+ ions, bases release OH− ions. pH scale measures acidity/basicity (0–14).
- Redox Reactions: Reactions involving the transfer of electrons. Oxidation is loss of electrons; reduction is gain.
Quick Tip
Use the acronym OIL RIG to remember redox: Oxidation Is Loss, Reduction Is Gain (of electrons).