Intermolecular Forces and Properties of Substances Flashcards

Vocabulary flashcards focusing on bonding types, Lewis structure principles, electronegativity ranges, VSEPR geometries, polarity rules, and intermolecular forces with liquid properties.

Ionic Bonding

Bonding between a metal and a non-metal involving complete electron transfer to form cations and anions.

Covalent Bonding

Bonding between non-metals involving electron sharing to form molecules.

Octet Rule

The goal for most atoms to have $8$ valence electrons, with the exception of Hydrogen which wants $2$.

NASU Method

A method for Lewis structures where N is Needed ($8$ for most, $2$ for H), A is Available, S is Shared ($N - A$), and U is Unshared ($A - S$).

Electronegativity

The ability of an atom to attract shared electrons in a bond.

Nonpolar Covalent Bond

A bond characterized by an electronegativity difference ($\Delta EN$) less than $0.4$.

Polar Covalent Bond

A bond characterized by an electronegativity difference ($\Delta EN$) between $0.4$ and $1.7$.

Ionic Bond Range

A bond formed when the electronegativity difference ($\Delta EN$) is greater than $1.7$.

VSEPR Theory

Valence Shell Electron Pair Repulsion theory, which states that valence electron pairs move as far apart as possible to minimize repulsion.

Linear Geometry

A molecular geometry characterized by a bond angle of $180^\circ$.

Trigonal Planar Geometry

A molecular geometry characterized by a bond angle of $120^\circ$.

Tetrahedral Geometry

A molecular geometry characterized by a bond angle of $109.5^\circ$.

Polar Molecule

A molecule possessing polar bonds and an asymmetrical shape where bond dipoles do not cancel.

Nonpolar Molecule

A molecule where bond dipoles cancel out due to symmetrical shape.

Intramolecular Forces

Strong forces existing within a molecule, such as ionic and covalent bonds.

Intermolecular Forces (IMFA)

Weak forces between separate molecules that are broken during phase changes.

London Dispersion Forces (LDF)

Intermolecular forces present in all molecules caused by temporary, instantaneous dipoles.

Dipole-Dipole Forces

Intermolecular forces occurring only between polar molecules where permanent partial positive ends attract permanent partial negative ends.

Hydrogen Bonding

A very strong IMFA that occurs when Hydrogen ($H$) is bonded to Nitrogen ($N$), Oxygen ($O$), or Fluorine ($F$).

Vapor Pressure

The pressure exerted by a vapor in equilibrium with its liquid.

Surface Tension

The energy required to increase the surface area of a liquid, creating a skin on top.

Viscosity

A liquid's resistance to flow.

Like Dissolves Like

The rule governing solubility stating that polar/ionic substances dissolve in polar solvents and nonpolar substances dissolve in nonpolar solvents.