Rate of Reaction

Simple and Giant Structures in Chemistry

Key Definitions

• ION: An atom that has lost or gained one or more electrons, resulting in an electric charge.

• IONIC BOND: The connection formed between ions to create a compound.

• IONIC COMPOUND: A compound formed when a metal ion and a non-metal ion react.

• MOLECULE: A particle resulting from atoms bonded together via covalent bonds.

• COVALENT BOND: A connection formed when atoms share electrons.

• ELECTRONIC STRUCTURE: Arrangement of electrons in shells around an atom's nucleus.

• INTERMOLECULAR FORCES: Forces acting between molecules.

• METALLIC BOND: The attraction between positively charged metal ions and a sea of delocalized electrons, allowing for conductivity and malleability.

Differences Between Ionic and Covalent Compounds

• Ionic compounds have different structural properties than molecular compounds, impacting their macroscopic physical properties.

• Physical Properties of Molecular Compounds:

  • Vary based on bonding type.

  • Generally have low melting and boiling points compared to ionic compounds, as melting involves breaking weaker intermolecular forces instead of strong ionic bonds.

Conductivity and Solubility

• Electrical Conductivity:

  • Covalent compounds: Poor conductivity in solid or liquid state.

  • Ionic compounds: Do not conduct electricity as solids; good conductors when molten or dissolved in solution.

• Water Solubility:

  • Varies for covalent compounds, depending on molecular structure.

  • Many ionic compounds are highly soluble in water.

Chemical Formulas

• Covalent compounds: Represent identity and exact number of atoms.

• Ionic compounds: Represent the simplest ratio of ions in a lattice.

Comparative Table of Ionic and Covalent Compounds

Simple Structures in Chemistry

• Simple Molecules: Groups of atoms bonded by covalent bonds, which can vary in type: monoatomic, diatomic, polyatomic (macromolecules).

Characteristics of Ionic and Covalent Bonds

• Ionic Bonding: Involves transfer of electrons between atoms; requires donor and acceptor.

• Covalent Bonding: Involves sharing electrons between atoms with similar electronegativity.

Giant Structures in Chemistry

• Giant Covalent Structures: Solid substances with very high melting points, all atoms bonded by strong covalent bonds (e.g., diamond, graphite, silicon dioxide).

• Giant Ionic Structures: Composed of large numbers of metal and non-metal ions in a regular lattice architecture.

Distinction Between Simple and Giant Structures

• Simple molecular substances are gases, liquids, or low melting point solids.

• Giant molecular structures are typically high melting point solids and can be ionic, metallic, or giant covalent.

• Giant Molecules: Known as macromolecules or polymers when formed by many combined molecules.

Comparison of Types of Bonding

Bonds Recap

• Ionic Bond: Formed between metals and non-metals, involving the transfer of electrons.

• Covalent Bond: Formed between non-metals, involving electron sharing.

• Giant Covalent Structure: Formed by covalent bonds among multiple atoms, revealing extensive bonding networks.

Vocabulary Words:

• Covalent: A type of chemical bond that involves the sharing of electron pairs between atoms.

• Monoatomic: Consisting of a single atom.

• Diatomic: Consisting of two atoms from the same or different chemical elements.

• Polyatomic: Consisting of more than two atoms.

• Macromolecules: Large, complex molecules, often consisting of many repetitive subunits (such as proteins or nucleic acids).