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Atomic Structure and Properties

• Atoms are the basic building blocks of matter, composed of a nucleus containing protons and neutrons, and electrons orbiting the nucleus.
• Protons have a positive charge, electrons have a negative charge, and neutrons have no charge.
• Atomic number represents the number of protons in an atom's nucleus.
• Mass number is the total number of protons and neutrons in an atom's nucleus.
• Isotopes are atoms of the same element with different numbers of neutrons.
• Atomic mass is the weighted average of the masses of all isotopes of an element.
• Electron configuration describes the arrangement of electrons in different energy levels and sublevels within an atom.
• Elements are arranged in the periodic table based on their atomic number and properties.
• Periodic trends include electronegativity, ionization energy, atomic radius, and metallic character, which change across periods and down groups.
• Valence electrons are electrons in the outermost energy level, determining an element's chemical reactivity.

Chemical Bonding

• Chemical bonds hold atoms together in molecules and compounds.
• Ionic bonds form between metals and nonmetals due to the transfer of electrons.
• Covalent bonds form between nonmetals due to the sharing of electrons.
• Metallic bonds involve a "sea" of electrons shared among metal atoms.
• Molecules are groups of atoms held together by covalent bonds.
• Molecular geometry describes the three-dimensional arrangement of atoms in a molecule, impacting its properties.

Chemical Reactions

• Chemical reactions involve the rearrangement of atoms to form new substances.
• Reactants are the substances that undergo change, and products are the substances formed.
• Chemical equations describe the reactions, with reactants on the left and products on the right.
• Coefficients in equations indicate the relative amounts of reactants and products.
• Types of reactions include synthesis, decomposition, single-displacement, double-displacement, and combustion.
• Reaction rates depend on factors like temperature, concentration, surface area, and catalysts.

States of Matter

• Matter exists in three fundamental states: solid, liquid, and gas.
• Solids have fixed shape and volume; liquids have fixed volume but variable shape; gases have neither fixed shape nor volume.
• Phase transitions involve changes between these states (e.g., melting, freezing, vaporization, condensation).

Solutions

• Solutions are homogeneous mixtures of two or more substances.
• Solvents are the dissolving medium, and solutes are the dissolved substances.
• Solubility describes the maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature and pressure.
• Concentration measures the amount of solute in a given amount of solution.
• Colligative properties of solutions depend on the number of solute particles, not their identity (e.g., vapor pressure lowering, boiling point elevation, freezing point depression).

Acids and Bases

• Acids and bases are characterized by their ability to donate or accept protons (H+ ions).
• pH measures the concentration of H+ ions, indicating acidity or basicity.
• Strong acids and bases ionize completely in water, while weak acids and bases only partially ionize.
• Neutralization reactions occur when acids and bases react to form water and a salt.

Thermodynamics

• Thermodynamics deals with energy changes in chemical and physical processes.
• Enthalpy (ΔH) measures the heat absorbed or released during a reaction.
• Entropy (ΔS) represents the disorder or randomness of a system.
• Gibbs Free Energy (ΔG) determines the spontaneity of a reaction.

Kinetics

• Chemical kinetics studies the rates of chemical reactions.
• Reaction mechanisms detail the steps involved in a reaction.
• Activation energy is the minimum energy needed for a reaction to occur.
• Catalysts increase reaction rates by lowering the activation energy.

Nuclear Chemistry

• Nuclear chemistry focuses on reactions involving atomic nuclei.
• Radioactive decay involves the spontaneous disintegration of unstable atomic nuclei.
• Nuclear reactions produce significant amounts of energy, as seen in nuclear power and nuclear weapons.