SC2a: Intramolecular and Intermolecular Forces

Intramolecular Forces

Forces that occur within a molecule, including covalent, ionic, and metallic bonds.

Covalent Bond

A type of intramolecular force where atoms share electrons, as seen in H₂O.

Ionic Bond

A type of intramolecular force where atoms transfer electrons, resulting in charged ions, as seen in NaCl.

Metallic Bond

A type of intramolecular force where electrons flow freely among a lattice of metal cations, characteristic of metals like copper.

Intermolecular Forces

Forces that occur between molecules, including London dispersion forces, dipole-dipole interactions, and hydrogen bonds.

London Dispersion Forces

The weakest intermolecular forces, present in all molecules, stronger in larger atoms/molecules.

Dipole-Dipole Interactions

Occur in polar molecules, where the positive end of one molecule attracts the negative end of another, such as in HCl.

Hydrogen Bonds

Strong interactions occurring in molecules where hydrogen is bonded to electronegative atoms like N, O, or F.

Melting Point

The temperature at which a solid becomes a liquid; influenced by intermolecular forces.

Boiling Point

The temperature at which a liquid becomes a gas; influenced by intermolecular forces and bonding.

Electrical Conductivity of Metals

The ability of metals to conduct electricity due to the movement of free electrons.

Polar Covalent Bonding

A type of bonding where electrons are shared unequally, leading to a dipole moment, as in H₂O.

Nonpolar Covalent Bonding

A type of bonding where electrons are shared equally, as seen in O₂.

Electronegativity

The tendency of an atom to attract electrons; influences bond type, such as in HCl.

Lewis Diagrams

A visual representation of the valence electrons in a molecule; shows how atoms are bonded.

Binary Ionic Compounds

Compounds composed of two different elements, typically consisting of a metal and a nonmetal.

Ternary Ionic Compounds

Ionic compounds that contain three or more elements, typically one of which is a polyatomic ion.

Ionic Compounds with Transition Metals

Ionic compounds where metallic elements have variable oxidation states, such as iron(II) chloride.

Inorganic Covalent Compounds

Covalent compounds that do not contain carbon-hydrogen bonds, like CO₂.

Acidic Compounds

Compounds that release H⁺ ions in solution, such as hydrochloric acid (HCl).

Writing Chemical Formulas

The process of representing substances with chemical symbols and numbers to show the elements and their proportions.