General Chemistry 1: Chapter 2 - Atoms, Molecules, and Ions

Objectives Overview

1. Fundamental Chemical Laws

   • Law of Conservation of Mass
   • Law of Definite Proportions
   • Law of Multiple Proportions

2. Dalton's Atomic Theory (1808)

   • Publication: New System of Chemical Philosophy
   • Theory of atoms

3. Basic Structure of an Atom

   • Comparison to modern understanding

4. Modern View of Atomic Structure

   • Composition of atoms
   • Differences in elements
   • Terminology: Atomic number, mass number, atomic weight, atomic mass unit, moles, molar mass

5. Molecules and Ions

   • Difference between covalent and ionic bonding

6. Introduction to the Periodic Table

   • Periodic table trends

7. Naming Simple Compounds

   • Rules for naming compounds

Historical Background

• Ancient Greeks and the fundamental substances: fire, earth, water, air
• Alchemy and its contributions
• Contributions of Robert Boyle and Antoine Lavoisier

Fundamental Chemical Laws

• Law of Conservation of Mass: Mass is neither created nor destroyed in chemical reactions.
• Law of Definite Proportions: Compounds always contain the same proportion of elements by mass.
• Law of Multiple Proportions: When two elements form multiple compounds, the ratios of the masses of the second element that combine with 1g of the first element are small whole numbers.

Dalton's Atomic Theory

• Atoms are the indivisible building blocks of matter.
• Atoms of a given element are identical; atoms of different elements differ.
• Chemical compounds are formed by combinations of different atoms.
• Chemical reactions involve reorganization of atoms.

Structure of the Atom

• Atoms consist of a nucleus (protons and neutrons) and electrons.
• Protons: Positively charged
• Neutrons: No charge
• Electrons: Negatively charged

Modern View and Terminology

• Atomic Number (Z): Number of protons in the nucleus.
• Mass Number (A): Total number of protons and neutrons.
• Atomic Weight: Weighted average of isotopic masses.
• Isotopes: Variants of elements with different numbers of neutrons.
• Moles and Avogadro's Number: 1 mole = 6.022 x 10^23 entities.
• Molar Mass: Mass of 1 mole of a substance.

Conversion Between Units

• Particles to moles: divide by Avogadro's number.
• Moles to particles: multiply by Avogadro's number.
• Moles to mass: multiply by molar mass.
• Mass to moles: divide by molar mass.

Molecules and Ions

• Ions are charged atoms (cat ions are positive, anion are negative).
• Covalent Bonds: Sharing of electrons.
• Ionic Bonds: Transfer of electrons forming charged ions.
• Electronegativity: Measure of an atom's ability to attract electrons.

Periodic Table and Trends

• Atomic Radius: Decreases across a period, increases down a group.
• Effective Nuclear Charge: Increases across a period, increases down a group.
• Ionization Energy: Increases across a period, increases up a group.
• Electronegativity: Increases across a period, increases up a group.
• Electron Affinity: Increases across a period, increases up a group.

Naming Simple Compounds

• Binary Compounds Type I: Name cation first, then anion with "-ide".
• Binary Compounds Type II: Transition metals, use Roman numerals for charge.
• Binary Covalent Compounds: Use prefixes (mono-, di-, tri-, etc.)
• Acids: Named based on presence of oxygen and type of anion.

Practice Problems

• Naming compounds and determining formulas using rules outlined.

This detailed overview serves as a comprehensive guide to understanding the foundational concepts of atoms, molecules, ions, and the systematic naming of chemical compounds in general chemistry.