Unit 2: Molecular and Ionic Compound Structure and Properties - Bonding Patterns

Chemical Bond

Attractive forces holding atoms together, driven by potential energy minimization.

Octet Rule

Atoms bond to achieve a stable electron configuration, typically resembling that of a noble gas.

Ionic Bonding

Electrostatic attraction between cations and anions due to electron transfer.

Covalent Bonding

Sharing of valence electrons between nuclei.

Nonpolar Covalent Bond

Electrons shared equally between atoms, resulting in no dipole.

Polar Covalent Bond

Electrons shared unequally, creating a dipole with partial charges.

Metallic Bonding

Attraction between positive metal ions and a sea of delocalized electrons.

Potential Energy Curve

Graph showing the relationship between potential energy and internuclear distance.

Bond Length

Distance at which attractive and repulsive forces are balanced, resulting in minimum energy.

Bond Energy

Energy required to break a bond; deeper wells indicate stronger bonds.

Coulomb's Law

Quantifies the strength of ionic interactions based on charge and distance.

Crystal Lattice

Continuous 3D array formed by ionic compounds.

High Melting Point

Characteristic of ionic solids, requiring substantial energy to break the lattice.

Brittleness

Tendency of ionic solids to shatter when layers shift, causing like charges to repel.

Conductivity in Solids

Ionic solids do not conduct electricity as ions are fixed in place.

Conductivity in Molten State

Ionic compounds conduct electricity when melted or dissolved, as ions are free to move.

Electron Sea Model

Model of metals where positive ions are surrounded by a sea of delocalized electrons.

Malleability

Ability of metals to be hammered into thin sheets due to non-directional bonding.

Ductility

Ability of metals to be drawn into wires; facilitated by the electron sea model.

Substitutional Alloys

Alloys formed by replacing host metal atoms with atoms of similar size.

Interstitial Alloys

Alloys formed when small atoms occupy spaces between larger host metal atoms.

Lattice Energy

Energy associated with the formation of the ionic lattice from its gaseous ions.

Difference in Electronegativity (ΔEN)

Plays a critical role in determining the type of bond formed between atoms.

Electrostatic Forces at Play

Affected by attraction and repulsion among nuclei and electron clouds.

Transition Metals Identification Pitfall

Do not assume bonds involving metals are ionic; consider properties.

Bond Energy vs. Lattice Energy Comparison

Bond energy relates to covalent bonds, while lattice energy relates to ionic solids.