CEM 141 – Chapter 4: Heterogeneous Compounds

A set of vocabulary flashcards for CEM 141 Chapter 4 covering various topics such as bonding, molecular geometry, and intermolecular forces.

Covalent Bonds

Bonds formed by the sharing of valence electrons between atoms.

Valence Electrons

Electrons in the outer shell of an atom that are involved in forming bonds.

Bond Length

The average distance between two bonded atoms in a molecule.

Bond Energy

The energy required to break one mole of a bond in a compound.

Hybrid Orbitals

Orbitals that are formed by the combination of atomic orbitals to accommodate electron hybridization.

Methane (CH4)

A simple compound consisting of one carbon atom bonded to four hydrogen atoms.

Lewis Structure

A diagram that shows the bonding between atoms of a molecule and the lone pairs of electrons.

Isomers

Compounds with the same molecular formula but different structural formulas.

Sigma Bond (σ bond)

A covalent bond formed by the head-on overlap of atomic orbitals.

Pi Bond (π bond)

A covalent bond formed by the side-to-side overlap of atomic orbitals.

Electronegativity

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

Polar Bond

A covalent bond between two atoms of different electronegativities, resulting in a dipole.

Dipole Moment

A measure of the polarity of a molecule, indicating the separation of positive and negative charges.

VSEPR Theory

A model used to predict the geometry of individual molecules based on the repulsion between electron pairs.

Tetrahedral Geometry

A molecular shape where a central atom is bonded to four other atoms at angles of approximately 109.5°.

Trigonal Planar Geometry

A molecular shape where a central atom is bonded to three other atoms in a flat plane at angles of 120°.

Bent Shape

A molecular shape that occurs when a central atom has two bonded atoms and one or more lone pairs.

Hydrogen Bonding

A strong type of dipole-dipole interaction that occurs between molecules containing hydrogen bonded to highly electronegative atoms.

Intermolecular Forces (IMFs)

Forces of attraction or repulsion between neighboring molecules or particles.

London Dispersion Forces

Weak intermolecular forces arising from temporary dipoles in molecules.

Dipole-Dipole Interactions

Attractive forces between polar molecules due to the positive and negative ends.

Ionic Bond

A chemical bond formed between two ions by the transfer of electrons.

Ion-Ion Interaction

The electrostatic attraction between oppositely charged ions in an ionic compound.

Formal Charge

The charge of an atom in a molecule calculated by comparing the number of valence electrons with the number of electrons assigned in the Lewis structure.

Polyatomic Ion

A charged ion composed of two or more atoms covalently bonded.

Cation

A positively charged ion formed by the loss of one or more electrons.

Anion

A negatively charged ion formed by the gain of one or more electrons.

Lattice Energy

The energy released when an ionic compound forms from its gaseous ions.

Hydrocarbons

Organic compounds consisting exclusively of hydrogen and carbon.

Alkenes

Hydrocarbons that contain at least one carbon-carbon double bond.

Alkynes

Hydrocarbons that contain at least one carbon-carbon triple bond.

Hydrocarbon Formula

A formula that represents hydrocarbons generally as CnH(2n+2) for alkanes without double or triple bonds.

Empirical Formula

The simplest whole-number ratio of the elements in a compound.

Molecular Shape

The three-dimensional arrangement of the atoms in a molecule.

Electrostatic Potential Map

A visual representation of the charge distribution within a molecule.

Space-Filling Model

A model that illustrates the three-dimensional structure of a molecule showing relative sizes of atoms.

Bond Angles

The angles between adjacent bonds in a molecule.

Chemical Properties

The characteristics that define how a substance interacts with other substances.

Physical Properties

The characteristics of a substance that can be observed without changing its identity.

Emergent Properties

Properties that arise from the collective interactions of a system's components.

Bonding Arrangements

The specific connections that hold atoms together in a molecule.