Metals and Their Properties

Metals

• Metals have delocalized valence electrons forming a "sea of electrons" enabling unique bonding.
• This leads to properties like conductivity and malleability.
• Nonmetals form localized covalent or ionic bonds, exhibiting different characteristics.
• Ductility is the ability to be drawn into wires, while malleability is the ability to be hammered or pressed into shapes.
• Thermal conductivity is the ability to conduct heat, and electrical conductivity is the ability to conduct electricity.
• Metals have luster, which is the way light interacts with their surfaces, creating a shiny appearance.
• Metals have crystalline structures with atoms arranged in repeating, closely packed patterns (BCC, FCC, HCP).
• These structures allow delocalized electrons to move freely, resulting in high electrical and thermal conductivity, malleability, and ductility.
• Metal atoms can slip past each other without breaking bonds, making them flexible and resistant to fracture.
• Point defects in crystals include interstitial, substitution, and vacancy defects.
• Dislocations occur when planes of atoms are inserted or removed.
• Alloys are mixtures of two or more elements (at least one a metal), such as steel (iron and carbon).

Water

• Water's unusual properties stem from its highly polar molecules and hydrogen bonding (strongest intermolecular force).
• Surface tension results from water molecules' tight adhesion at the surface, allowing small objects to float and insects to walk on water.
• A surfactant reduces surface tension, increasing wetting.
• Water's liquid state at standard temperature and pressure (STP) is due to its 100°C boiling point.
• Water expands and becomes less dense as it freezes, unlike other substances.
• The solvent is the dissolving medium, the solute is the dissolved particles, solvation is the process of ion capture by the solvent.
• An aqueous solution has water as the solvent.
• Electrolytes conduct electric current in aqueous or molten states, while nonelectrolytes do not.
• Hydrates are crystalline compounds with integral water molecules in their structure.
• Efflorescence is the loss of water by a hydrate.

Solutions

• Dissolution rate is the speed at which a solute dissolves, affected by solute structure (particle size) and processing (heating/agitating).
• A saturated solution holds the maximum solute at a given temperature and pressure.
• Solubility is the amount of solute dissolved in a solvent to form a saturated solution, determined by temperature and pressure.
• Solubility curves show solubility as a function of temperature.
• Solubility of gases decreases with increasing temperature.
• Hypoxic zones in the ocean have low oxygen levels, harming aquatic life.
• Supersaturated solutions hold more solute than theoretically possible. Crystallization can be initiated by a seed crystal, resulting in rapid solute deposition.
• Henry's Law describes the relationship between solubility and pressure (S1/P1 = S2/P2).
• Solutions are homogeneous mixtures (uniform appearance and composition).
• Heterogeneous mixtures lack uniform composition and are not solutions.
• Colloids are heterogeneous mixtures with dispersed particles throughout a medium.
• Suspensions are heterogeneous mixtures where particles settle upon standing.
• The key physical difference between colloids and suspensions is particle size.