Chemical Bonding, Molecular Structures, and Intermolecular Forces

Comprehensive vocabulary flashcards covering chemical bonding, ionic and molecular nomenclature, electronegativity trends, Lewis structures, molecular polarity, intermolecular forces, water properties, and sustainable materials.

Chemical Bond

The force of attraction holding two atoms or ions together in a compound.

Ionic Bond

The electrostatic force of attraction between a positive ion (cation) and a negative ion (anion), created by the transfer of valence electrons between atoms.

Crystal Lattice Structure

The rigid, three-dimensional arrangement of large numbers of repeating positive and negative ions held in a fixed ratio in an ionic compound.

Formula Unit

The smallest repeating unit in an ionic crystal lattice structure.

Electrolyte

A substance that dissolves in water to produce free-floating ions that conduct electricity.

Binary Ionic Compound

An ionic compound composed of only two different elements: a metallic cation and a non-metallic anion ending in "-ide."

Multivalent Metal

A metal that can form a variety of cations each carrying a different charge (such as $Fe^{2+}$ and $Fe^{3+}$), specified in nomenclature with Roman numerals in parentheses.

Polyatomic Ion

A single unit composed of two or more elements joined by covalent bonds that carries an overall electric charge shared across the entire ion.

Oxyanion

A negatively charged polyatomic ion consisting of oxygen combined with another non-metal element.

Parent Oxyanion

The most stable and common combination of a non-metal with oxygen, named using the stem of the non-metal and the suffix "-ate" (e.g., chlorate, $ClO_3^-$).

Per- / -ate Oxyanion Rule

The naming convention applied when an oxyanion has one more oxygen atom ($x+1$) than its parent "-ate" ion, using the prefix "per-" and the suffix "-ate" (e.g., perchlorate, $ClO_4^-$).

-ite Oxyanion Rule

The naming convention applied when an oxyanion has one fewer oxygen atom ($x-1$) than its parent "-ate" ion, changing the suffix to "-ite" (e.g., chlorite, $ClO_2^-$).

Hypo- / -ite Oxyanion Rule

The naming convention applied when an oxyanion has two fewer oxygen atoms ($x-2$) than its parent "-ate" ion, using the prefix "hypo-" and the suffix "-ite" (e.g., hypochlorite, $ClO^-$).

Zero-Sum Rule

The principle stating that the total positive charge of the cations in an ionic compound must equal the total negative charge of the anions to produce an electrically neutral compound.

Hydrate

An ionic compound that contains a fixed ratio of water molecules bound within its crystal structure.

Bluestone

The common household name for a hydrate of copper(II) sulfate ($CuSO_4 \times 5H_2O$).

Electronegativity

The relative ability of an individual atom, when bonded, to attract bonding electrons toward itself.

Linus Pauling Scale

The electronegativity scale developed in 1922 that assigns the highest value to fluorine ($4.0$) and the lowest value to francium ($0.7$).

Electronegativity Difference ($\Delta EN$)

The difference between the electronegativities of two bonded atoms, used to predict whether a chemical bond is non-polar covalent, polar covalent, or ionic.

Non-Polar Covalent Bond

A covalent bond formed between two identical or nearly identical atoms ($\Delta EN = 0$) where bonding electron pairs are shared equally.

Polar Covalent Bond

A covalent bond formed between atoms with a significant electronegativity difference ($0 < \Delta EN < 1.7$) causing unequal sharing of electrons and resulting in partial charges ($\delta^+$ and $\delta^-$).

Covalent Bond

A chemical bond created by the sharing of one or more pairs of valence electrons between atoms.

Bonding Capacity

The number of covalent bonds an atom can form, which corresponds to the number of unpaired valence electrons needed to complete an octet.

Lewis Structure

A structural diagram representing molecular substances that shows lone pairs of electrons as dots and shared bonding pairs as lines (or pairs of dots).

Structural Formula

A chemical representation showing the arrangement of atoms and covalent bonds in a molecule using lines for shared pairs while omitting lone pairs.

Polar Molecule

A molecule that has an asymmetrical distribution of charge, resulting in a positively charged end ($\delta^+$) and a negatively charged end ($\delta^-$).

Non-Polar Molecule

A molecule in which charges are distributed equally, either because it contains only non-polar bonds or because its polar bonds are arranged symmetrically so their dipole vectors cancel.

Intermolecular Force

A force of attraction acting between separate molecules that determines bulk physical properties like boiling point, melting point, and surface tension.

van der Waals Forces

The collective term for intermolecular dipole-dipole forces and London dispersion forces, named after Dutch physicist Johannes van der Waals.

London Dispersion Forces (LDF)

The weakest intermolecular force caused by random, temporary shifts in electron clouds that create instantaneous dipoles, which induce dipoles in neighboring molecules; occurs in all atoms and molecules.

Dipole-Dipole Forces

Moderate electrostatic attractions between the permanent partial positive ($\delta^+$) end of one polar molecule and the partial negative ($\delta^-$) end of an adjacent polar molecule.

Hydrogen Bonding

An exceptionally strong, specialized dipole-dipole force occurring when hydrogen is covalently bonded directly to a highly electronegative atom ($F$, $O$, or $N$) with a high charge density.

Density Anomaly of Water

The unusual physical property of water where liquid water is densest at $4\,^\circ\text{C}$ and expands upon freezing due to hydrogen bonds arranging molecules into an open hexagonal crystalline lattice.

Specific Heat Capacity of Water

The unusually high amount of thermal energy required to raise the temperature of water, caused by the large number of hydrogen bonds that must absorb energy before molecules move faster.

Surface Tension

The cohesive force at the surface of a liquid resulting from unbalanced intermolecular attractions pulling surface molecules inward toward each other.

Renewable Resource

A natural substance that replenishes itself as it is used, such as wood, water, or agricultural crops like corn and sugar cane.

Non-Renewable Resource

A natural substance that cannot be replaced as quickly as it is consumed, such as crude oil, petroleum, or aluminum ore.

Petrochemical

A synthetic chemical compound manufactured from a fossil fuel resource.

Recycling

The industrial process of converting a discarded product back into a raw material that can be re-manufactured into new goods.

Biodegradable

Capable of being broken down rapidly through the biological action of moisture, heat, and microorganisms.

Compostable

The ability of organic material to decompose naturally into a nutrient-rich product capable of sustaining plant growth.

Upcycling

The creative reuse of discarded materials or waste products into new items of higher artistic, environmental, or economic value (such as lunch bags made from candy wrappers).

Polylactic Acid (PLA)

A renewable, biodegradable thermoplastic polyester synthesized from fermented plant starch such as corn.