Chemical Bonding, Molecular Compounds, and Lewis Structures

Vocabulary flashcards covering chemical bonds, ionic and covalent compound properties, intermolecular forces, and Lewis structure drawing methods.

Chemical Bond

The attractive force that holds groups of 2 or more atoms together and makes them function as a unit.

Cation

A positively charged ion.

Anion

A negatively charged ion.

Ion

A charged particle formed from the loss or gain of electrons.

Ionic Bond

The attraction between oppositely charged ions, formed by permanent forces of attraction between a positive and negative ion when the difference in electronegativity is greater than $1.7$.

Ionic Compound

An electrically neutral compound formed when metal cations chemically bond to non-metal anions; characterized by hard, rigid, and brittle crystalline solids with high melting and boiling points.

Electrolyte

An ionic compound that conducts electricity in a solution when dissolved in water or when molten, because charged particles become free to move.

Formula Unit

The smallest ratio of an ionic compound.

Covalent Bond

A chemical bond created when nonmetal atoms share pairs of electrons to obtain a full octet (valence shell), occurring when differences in electronegativities are less than $1.7$.

Covalent Compound

A substance formed when 2 or more non-metal atoms share valence electrons to create molecules; characterized by weak bonds that are easily broken, low melting and boiling points, and no electrical conductivity.

Molecule

A collection of atoms bonded together that behave as a unit; represents the smallest particle of a covalent compound.

Single Covalent Bond

A covalent bond formed when atoms share $1$ electron pair.

Double Covalent Bond

A covalent bond formed when atoms share $2$ electron pairs.

Triple Covalent Bond

A covalent bond formed when $2$ atoms share $3$ electron pairs.

Polar Covalent Bond

A covalent bond resulting from the unequal sharing of electrons between different atoms.

Non-polar Covalent Bond

A covalent bond formed by the equal sharing of pairs of electrons between non-metal atoms or two atoms of the same element.

Mostly Covalent Bond

A bond characterized by an electronegativity difference ranging from $0.4$ to above $0$.

Metallic Bond

A bond formed when many metal atoms share all valence electrons, creating a "sea of delocalized electrons".

Hydrogen Bond

An intermolecular attraction formed when hydrogen is bonded with a highly electronegative atom.

Dispersion Forces

Weak intermolecular attractions caused by an electron shift.

Dipole-Dipole Forces

Electrostatic attractions between the positive and negative ends of polar molecules.

Lewis Structure

A graphical 2-dimensional representation of molecular compounds used to determine molecular shape and polarity, using lines for shared bonding pairs and dots for lone non-bonding pairs on the central atom.

Lewis Structures: Method 1

A 3-step drawing process: 1. Make electron dot structures; 2. Use formula to create a Lewis structure with bonds represented as lines (combining lone electrons into lines if an atom lacks $8$ electrons); 3. Create a VSEPR shape.

Lewis Structures: Method 2

A 5-step drawing process: 1. Determine total valence electrons for all atoms; 2. Determine central atom; 3. Place bonding pairs between central and outer atoms and subtract bonding pairs from total; 4. Determine electrons needed to satisfy the octet rule ($8$ electrons); 5. Place remaining electrons as bonds around the atom.

Octet Rule

The principle that atoms share, lose, or gain valence electrons to obtain a full outer valence shell of $8$ electrons.