01-Phillips-Ch01

General Outcomes

  • Describe the role of modeling, evidence, and theory in understanding ionic and molecular compounds.

Unit Contents

Chapter 1: Chemical Bonding

  • Focus on how chemical bonding affects the properties of materials.

Chapter 2: Diversity of Matter

Focusing Questions

  1. Why do some substances dissolve easily while others do not?

  2. Why do different substances have varying boiling and melting points?

  3. How can models enhance our understanding of bonding?

Introduction to Chemical Bonding

  • Diamonds: hardest known substance used in mining.

  • Properties of substances influenced by atomic structure.

  • Historical context: Understanding of atomic structure and bonding evolved over a century.

  • Overview: Study bonding to understand properties of materials like diamond's hardness and gold's malleability.

Atoms, Elements, and Isotopes

  • Modern theory: Atoms consist of a positively charged nucleus surrounded by negatively charged electrons.

  • Nucleus contains protons (positive) and neutrons (neutral).

  • Atoms of the same element can have different isotopes (same protons, different neutrons) represented as X (A/Z).

Periodic Table

  • Developed by Dmitri Mendeleev in 1869 based on atomic properties.

  • Elements organized by increasing atomic number and similar properties in groups.

Classes of Elements

  • Metals: Solid, shiny, good conductors, malleable, ductile.

  • Metalloids: Somewhat conductive, brittle, varied appearance.

  • Non-metals: Gases or brittle solids, poor conductors.

Characteristics of Elements in the Periodic Table

  • Metals lose electrons while non-metals gain them in forming bonds.

  • Non-metals share electrons while forming covalent bonds.

Bonding Overview

Ionic Bonds

  • Formed from metal losing electrons and non-metal gaining them.

  • Resulting charged ions attract each other.

Covalent Bonds

  • Non-metals share electrons to fill their valence shells.

Electron Energy Levels

  • Electrons exist in specific energy levels around the nucleus.

  • Valence electrons determine chemical bonding.

Electron Dot Diagrams

  • Visualize electron sharing for bonding.

Ionic Compounds Naming and Formulas

  • Binary ionic compounds: Metal name + non-metal name with "-ide" ending.

  • Roman numerals indicate charge for metals with multiple oxidation states.

Covalent Compounds Naming and Formulas

  • Naming based on the number of atoms using prefixes.

  • Example: CO2 - carbon dioxide.

Polyatomic Ions

  • Positively or negatively charged ions made of multiple atoms.

Naming Rules

  1. Name of the positive ion comes first.

  2. Negative ion name follows.

  3. Net compound charge is neutral.

Chemical Reactivity

  • Electronegativity: measure of an atom's ability to attract electrons.

  • Electronegativity trends in the periodic table affect bond character (ionic versus covalent).

key Terms Review

  • Electronegativity, polar bonds, and bond dipoles discussed.

Conclusion

  • Chemical bonding is central to understanding material properties and reactions.

  • The octet rule and electron pairs determine bond formation.