Chemistry Lecture Notes

Introduction

• Focus on introductory chemistry
• Useful for beginners or those starting a chemistry course

Periodic Table Overview

Group 1: Alkali Metals

• Elements: H (Hydrogen), Li (Lithium), Na (Sodium), K (Potassium), Rb (Rubidium), Cs (Cesium)
• Characteristics: Forms ions with a +1 charge
• Note: Alkali metals are highly reactive (except Hydrogen)

Group 2: Alkaline Earth Metals

• Elements: Be (Beryllium), Mg (Magnesium), Ca (Calcium), Sr (Strontium), Ba (Barium)
• Characteristics: Forms ions with a +2 charge

Group 13 (3A)

• Elements: B (Boron), Al (Aluminum), Ga (Gallium)
• Characteristics: Can form +3 charges

Group 14 (4A)

• Elements: C (Carbon), Si (Silicon), Ge (Germanium), Sn (Tin)
• Characteristics: Can have multiple oxidation states (+2, +4)

Group 15 (5A)

• Elements: N (Nitrogen), P (Phosphorus)
• Characteristics: Typically form -3 charges

Group 16 (6A)

• Elements: O (Oxygen), S (Sulfur)
• Characteristics: Typically form -2 charges

Group 17 (7A): Halogens

• Elements: F (Fluorine), Cl (Chlorine), Br (Bromine), I (Iodine)
• Characteristics: Typically form -1 charges

Group 18 (8A): Noble Gases

• Elements: He (Helium), Ne (Neon)
• Characteristics: Chemically inert, stable

Transition Metals (Groups 3-12)

• Common Elements: Ti (Titanium), Cr (Chromium), Fe (Iron), Ni (Nickel), Cu (Copper)

Inner Transition Metals

• Series: Lanthanide and Actinide
• Important Elements: Th (Thorium), U (Uranium)

Basic Chemistry Concepts

Atoms vs. Molecules

• Atoms: Single units, e.g., Zn (Zinc), Fe (Iron)
• Molecules: Composed of two or more atoms, e.g., H2 (Hydrogen gas), O2 (Oxygen gas)

Elements vs. Compounds

• Elements: Pure substance, one type of atom
• Compounds: Two or more different atoms
  • Ionic Compounds: Composed of metals and nonmetals
  • Molecular Compounds: Made up of nonmetals

Metals, Nonmetals, and Metalloids

• Metals: Conduct electricity, form cations
• Nonmetals: Insulators, form anions
• Metalloids: Properties between metals and nonmetals

Naming Compounds

Molecular Compounds

• Use prefixes (mono-, di-, tri-, etc.)
• Examples:
  • CO2: Carbon Dioxide
  • N2O5: Dinitrogen Pentoxide

Ionic Compounds

• Name metal first, nonmetal with 'ide' suffix
• Examples:
  • KI: Potassium Iodide
  • MgBr2: Magnesium Bromide

Polyatomic Ions

• Common ions: SO4²⁻ (Sulfate), OH⁻ (Hydroxide), NH4⁺ (Ammonium)
• Recognize these ions in compounds

Chemical Formulas

Molecular Compound Formulas

• Based on prefixes, e.g., PCl5 (Phosphorus Pentachloride)

Ionic Compound Formulas

• Balance charges, e.g., Al₂(SO₄)₃ (Aluminum Sulfate)

Isotopes and Atomic Structure

Isotopes

• Same number of protons, different neutrons
• Examples: Carbon-12 and Carbon-13

Atomic Calculations

• Protons: Equal to atomic number
• Neutrons: Difference between mass number and atomic number
• Electrons: Equal to protons in neutral atoms, adjust for charge in ions

Practice Problems

• Determine protons, neutrons, electrons for given isotopes and ions

Conclusion

• Understanding the periodic table, chemical naming, and atomic structure is foundational in chemistry.
• Practice identifying elements and compounds, and calculating atomic structure values for proficiency.