1: Primer
- Page ID
- 362275
Chemistry is all around us "from the air we breathe to the food we eat" to the items at the super market that say “no chemicals added”. In fact, it is impossible to create something without using chemistry because chemistry consists of all matter. It allows us to answer questions as simple as why a candle goes out when a glass is placed over it to more complex questions such as does a candle actually burn in zero gravity? Chemistry is the study of matter and the changes it undergoes such as ice changing from the solid to liquid to gas phase. People have used it for things such as creating metal from an ore, dying fabric, and making cheese. Chemistry deals with different substances and how they can interact with each other to create a product.
As you begin your study of college chemistry, those of you who do not intend to become professional chemists may well wonder why you need to study chemistry. You will soon discover that a basic understanding of chemistry is useful in a wide range of disciplines and career paths. You will also discover that an understanding of chemistry helps you make informed decisions about many issues that affect you, your community, and your world. A major goal of this text is to demonstrate the importance of chemistry in your daily life and in our collective understanding of both the physical world we occupy and the biological realm of which we are a part.
- 1.2: Chemical Bonding - Electron Pairs and Octets
- Theories of chemical bonding invariably involve electrons. When one atom approaches another, the valence electrons, found in the outermost regions of the atoms, interact long before the nuclei can come close together. Electrons are the least massive components of an atom, and so they can relocate to produce electrostatic forces which hold atoms together.
- 1.2.1: Prelude to Chemical Bonding
- 1.2.2: Ionic Bonding
- 1.2.3: Energy and the Formation of Ions
- 1.2.4: The Ionic Crystal Lattice
- 1.2.5: Ions and Noble-Gas Electron Configurations
- 1.2.6: Ionization Energies
- 1.2.7: Ionization of Transition and Inner Transition Elements
- 1.2.8: Electron Affinities
- 1.2.9: Binary Ionic Compounds and Their Properties
- 1.2.10: The Octet Rule
- 1.2.11: Physical Properties
- 1.2.11.1: Lecture Demonstrations
- 1.2.12: Chemical Properties
- 1.2.13: The Covalent Bond
- 1.2.14: Covalent Molecules and the Octet Rule
- 1.2.15: Writing Lewis Structures for Molecules
- 1.2.15.1: An Excess of Bonds
- 1.2.15.2: Deciding on a Skeleton Structure
- 1.2.15.3: Multiple Bonds
- 1.2.16: Examples of Lewis Structures
- 1.2.17: Polyatomic Ions
- 1.2.18: Ionic Compounds Containing Polyatomic Ions
- 1.2.19: Atomic Sizes
- 1.2.20: Ionic Sizes
- 1.2.21: Periodic Variation of IE and EA
- 1.2.21.1: Lecture Demonstrations
- 1.3: Further Aspects of Covalent Bonding
- In the following sections, we will develop a more detailed picture of molecules—including some which do not obey the octet rule. You will learn how both the shapes and bonding of molecules may be described in terms of orbitals. In addition it will become apparent that the distinction between covalent and ionic bonding is not so sharp as it may have seemed. You will find that many covalent molecules are electrically unbalanced, causing their properties to tend toward those of ion pairs. Rules wil
- 1.3.1: Prelude to Covalent Bonding
- 1.3.2: Exceptions to the Octet Rule
- 1.3.2.1: Biology- Biologically Active Exceptions to the Octet Rule
- 1.3.3: The Shapes of Molecules
- 1.3.3.1: Lecture Demonstrations
- 1.3.4: Molecules with Lone Pairs
- 1.3.4.1: Lecture Demonstrations
- 1.3.5: Multiple Bonds and Molecular Shapes
- 1.3.6: Hybrid Orbitals
- 1.3.7: Orbital Descriptions of Multiple Bonds
- 1.3.8: Sigma and Pi Bonds
- 1.3.9: Polarizability
- 1.3.9.1: Biology - Polarizability of Biologically Significant Atoms
- 1.3.10: Polar Covalent Bonds
- 1.3.10.1: Biology- Nonpolar Iodine and Polar Hydrogen Iodide
- 1.3.10.2: Lecture Demonstrations
- 1.3.11: Electronegativity
- 1.3.12: Polarity in Polyatomic Molecules
- 1.3.12.1: Biology- The Hydrophobic Effect and Properties of Small Polyatomic Molecules
- 1.3.12.2: Lecture Demonstrations
- 1.3.13: Formal Charge and Oxidation Numbers
- 1.3.14: Resonance
- 1.4: Properties of Organic Compounds
- Hydrogen, oxygen, nitrogen, and a number of other elements also bond strongly to carbon, and a tremendous variety of compounds can result. In the early days of chemistry such compounds were obtained from plants or animals rather than being synthesized by chemists, and so they came to be known as organic compounds. This distinguished them from the inorganic compounds available from nonliving portions of the earth’s surface.
- 1.4.1: Prelude to Organic Compounds
- 1.4.2: Covalent Compounds and Intermolecular Forces
- 1.4.3: Dipole Forces
- 1.4.4: London Forces
- 1.4.4.1: <pic>Chapter 8 page 3.jpg
- 1.4.4.2: Atomic Radii
- 1.4.4.3: Atomic sizes on periodic table.jpg
- 1.4.4.4: Ionization Energies
- 1.4.4.4.1: <pic> IonizationEnergyAtomicWeight.PNG
- 1.4.4.5: Ionization Energies and Electron Affinities
- 1.4.4.5.1: Electron Affinities
- 1.4.4.5.1.1: <pic> Ionization Energies and Electron Affinities.jpg
- 1.4.4.6: Polarizability on London Forces.jpg
- 1.4.5: Hydrogen Bonding- Water
- 1.4.5.1: Atomic Radii and Ionic Radii
- 1.4.5.2: H-Bonding Between 2 HF Molecules.jpg
- 1.4.5.3: Nonmetal hydride bp.jpg
- 1.4.6: Ice and Water
- 1.4.6.1: <pic> Ice; a hexagonal crystal.jpg
- 1.4.6.2: Boiling Points of Hydrides
- 1.4.7: Macromolecular Substances
- 1.4.8: Diamond and Graphite
- 1.4.9: Silicon Dioxide
- 1.4.10: Synthetic Macromolecules- Some Applied Organic Chemistry
- 1.4.11: Addition Polymers
- 1.4.12: Condensation Polymers
- 1.4.13: Cross-Linking