Chemistry Final Review

📘 Study Guide Summary

I. Measurement and Calculation

Metric Prefixes

• Kilo (1000)

• Deci (0.1)

• Centi (0.01)

• Milli (0.001)

Mnemonic: “King Henry Died Drinking Chocolate Milk.”

Common Units

• Mass: Kilogram (kg)

• Volume: Liter (L), Milliliter (mL)

• Length: Meter (m)

Conversions

• 1 mL = 0.001 L

• 1 g = 0.001 kg

Example:

Density Formula

Mnemonic: “Don’t Make Violets.”

II. Matter and Change

States of Matter

• Solid: Definite shape and volume, particles are tightly packed.

• Liquid: Definite volume, no definite shape, particles slide past each other.

• Gas: No definite shape or volume, particles are scattered.

Mnemonic: Ice (solid), Water (liquid), Steam (gas).

Mixtures

• Homogeneous: Uniform (e.g., saltwater).

• Heterogeneous: Non-uniform (e.g., oil and water).

Separation Example:

• Evaporate water to leave salt behind.

Signs of a Chemical Reaction

• Color change

• Gas formation

• Precipitate formation

• Odor change

• Temperature change

Mnemonic: “Can’t Great People Order Tacos?”

Law of Conservation of Mass

• Matter cannot be created or destroyed in a reaction.

Example: Reactants → ____

III. Chemical Bonding

Chemical Bond Basics

• Definition: A force that holds atoms together using valence electrons.

Mnemonic: “Valence Veil” — Valence electrons connect atoms like a veil.

Types of Bonds

• Ionic: Transfer of electrons (Metal + Nonmetal).

• Covalent: Sharing of electrons (Nonmetal + Nonmetal).

• Metallic: Free-flowing electrons in a “sea of electrons.”

Mnemonic: “ICM” → Ionic, Covalent, Metallic.

Bond Examples

• Ionic Bond: NaCl (salt).

• Covalent Bond: H₂O (water).

• Metallic Bond: Aluminum foil.

Mnemonic: “Metal to Nonmetal Marriage” for ionic bonds.

Diatomic Elements

• H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂.

Mnemonic: “Have No Fear Of Ice Cold Beer.”

Molecular Compounds Properties

• Often gases.

• Low melting/boiling points.

• Soft solids.

Mnemonic: “GLS” → Gas, Low, Soft.

Lewis Structures

• Depict how atoms share electrons.

Mnemonic: “Lewis Needs Electrons.”

IV. Atomic Structure and Nuclear Chemistry

Key Terms

• Atom: Smallest unit of an element.

• Proton: Positive, located in the nucleus.

• Neutron: Neutral, located in the nucleus.

• Electron: Negative, located in the cloud.

Mnemonic: “Protons are Positive, Neutrons are Neutral, Electrons are Elsewhere.”

Important Scientists

• Dalton: Atomic theory (atoms are indivisible).

• Mendeleev: Created the periodic table.

• Moseley: Discovered atomic number.

• Bohr: Electron orbits.

• Chadwick: Discovered neutrons.

Mnemonic: “Daring Men Make Bold Choices.”

Radiation Types

• Alpha: Heavy, stopped by paper.

• Beta: Lighter, stopped by aluminum.

• Gamma: Energy only, stopped by lead.

Mnemonic: “Alpha is hefty, Beta is better, Gamma is gone through!”

V. Electrons in Atoms

Electron Configurations

• Mnemonic: Use the periodic table to “read” electron configurations row by row.

Trends on the Periodic Table

• Atomic Radius: Increases down, decreases across.

• Ionization Energy: Decreases down, increases across.

• Electronegativity: Decreases down, increases across.

Mnemonics for Trends:

• Atomic Radius: “Rivers grow DOWN.”

• Ionization Energy: “I Energy UP.”

• Electronegativity: “Electrons Need More UP.”

VI. The Periodic Table

Groups and Families

• Alkali Metals: Group 1

• Alkaline Earth Metals: Group 2

• Halogens: Group 17

• Noble Gases: Group 18

Mnemonic: Alkali soup, Earth veggies, Halogen salt, Noble wine.

Metals, Nonmetals, Metalloids

• Metals: Left of the staircase.

• Nonmetals: Right of the staircase.

• Metalloids: Along the staircase.

VII. Nomenclature

Ionic Compounds

• Metal + Nonmetal

• Properties:

• High melting/boiling points.

• Crystalline solids.

• Conduct electricity when dissolved.

Mnemonic: “Metal to Nonmetal Marriage.”

Molecular Compounds

• Nonmetal + Nonmetal

• Properties: Low melting points, often gases.

Mnemonic: “GLS” → Gas, Low, Soft.

Acids

• Binary Acid: Hydro- + root + -ic acid (e.g., HBr → Hydrobromic acid).

• Oxyacids: Change -ate to -ic, -ite to -ous.

Bases

• End with OH (e.g., NaOH → Sodium hydroxide).

Classification Summary

• Ionic (I): Metal + Nonmetal

• Molecular (M): Nonmetal + Nonmetal

• Acid (A): Starts with H

• Base (B): Ends with OH

Mnemonic: “I Make All Bases Clear.”