Covalent Bonding

• What is the main focus of Chapter 7 in the Principles of Chemistry?

  Understanding covalent bonding
• Why is it important to understand covalent bonding?

  There are more covalent compounds than ionic compounds
• What type of compound is water?

  Water is a covalent compound
• What is formed between atoms in a covalent bond?

  A pair of electrons is shared
• How can covalent bonds be represented?

  Using dot-and-cross diagrams
• What types of molecules can be represented using dot-and-cross diagrams?

  • Diatomic molecules (e.g., hydrogen, oxygen, nitrogen, halogens, hydrogen halides)
  • Inorganic molecules (e.g., water, ammonia, carbon dioxide)
  • Organic molecules (e.g., methane, ethane, ethene, halogen-containing compounds)
• Why are substances with a simple molecular structure typically gases or liquids?

  They have low melting and boiling points
• What term is used to represent all forces between molecules?

  Intermolecular forces of attraction
• How does the relative molecular mass affect the melting and boiling points of substances with simple molecular structures?

  Melting and boiling points generally increase with increasing relative molecular mass
• Why do substances with giant covalent structures have high melting and boiling points?

  They have strong covalent bonds throughout the structure
• How do the structures of diamond, graphite, and C60 fullerene influence their physical properties?

  • Diamond: Hard, non-conductive
  • Graphite: Soft, conductive due to delocalized electrons
  • C60 Fullerene: Unique structure with varying properties
• Do covalent compounds usually conduct electricity?

  No, they do not usually conduct electricity
• What holds the atoms together in a covalent bond?

  The strong electrostatic attraction between the nuclei and the shared pair of electrons
• What is shared between two atoms in a covalent bond?

  A pair of electrons
• What type of charge do the nuclei of the atoms in a covalent bond have?

  Positive charge
• What type of charge do the shared electrons in a covalent bond have?

  Negative charge
• How does the concept of electrostatic attraction apply to covalent bonding?

  It explains how positively charged nuclei attract negatively charged shared electrons