CHEM 108 Health Chemistry I - Exam 2 Review

Comprehensive vocabulary flashcards covering key topics, definitions, chemical bonding concepts, reaction types, and stoichiometry for CHEM 108 Exam 2.

Isotope

Atoms of the same element that contain equal numbers of protons but different numbers of neutrons, resulting in different isotopic masses.

Average Atomic Mass (Atomic Weight)

The weighted average mass of an element calculated using the fractional or percent abundance and the atomic mass of each naturally occurring isotope.

Mole

The standard SI unit for amount of substance, defining a quantity that contains Avogadro's number of particles.

Avogadro's Number

The number of representative particles (atoms, molecules, or formula units) present in one mole of any substance, equal to $6.022 \times 10^{23}$ particles.

Molar Mass

The mass of one mole of a chemical element or compound, typically expressed in units of grams per mole ($\text{g/mol}$).

Cation

A positively charged ion formed when a neutral atom loses one or more valence electrons.

Anion

A negatively charged ion formed when a neutral atom gains one or more electrons.

Polyatomic Ion

A charged chemical species composed of two or more covalently bonded atoms carrying a net positive or negative charge.

Ionic Compound

A compound composed of cations and anions bound together by electrostatic attractions (ionic bonds).

Molecular Compound

A chemical compound composed of discrete molecules held together by covalent bonds formed through the sharing of electrons.

Valence Electrons

Electrons residing in the outermost electron shell of an atom that participate in the formation of chemical bonds.

Lewis Electron Dot Structure

A structural representation that depicts an atom, ion, polyatomic ion, or molecule showing valence electrons as dots and shared pairs as lines.

Octet Rule

The chemical principle that main group atoms tend to form bonds until they are surrounded by eight valence electrons, though certain exceptions exist.

Formal Charge

The hypothetical charge assigned to an individual atom in a Lewis structure, calculated to evaluate and determine the most stable electron dot distribution.

Resonance Structures

Two or more valid Lewis structures for a single molecule or ion that cannot be accurately represented by only one diagram, resulting in a resonance hybrid.

VSEPR Theory

Valence Shell Electron Pair Repulsion theory; a model used to predict the electron-group geometry of molecules based on minimizing electrostatic repulsion between electron pairs.

Electron-Group Geometry

The three-dimensional spatial arrangement of all electron groups (both bonding pairs and lone pairs) surrounding the central atom.

Molecular Geometry

The three-dimensional spatial arrangement of only the bonded atoms around the central atom in a molecule or polyatomic ion.

Bond Angle

The geometric angle formed between two adjacent covalent bonds sharing a common central atom, which can be altered or compressed by nonbonding lone pairs.

Electronegativity

A measure of the ability of an atom in a chemical bond to attract shared bonding electrons toward itself.

Bond Polarity

The uneven distribution of electron density between two bonded atoms, determined by the magnitude of their electronegativity difference.

Dipole Moment

A quantitative measurement of the polarity of a chemical bond or molecule, reflecting the magnitude and direction of separated electric charge.

Subscript

A small number placed to the lower right of a chemical element symbol indicating the relative ratio or number of atoms of that element in a formula.

Coefficient

A whole number placed directly in front of a chemical formula in a balanced chemical equation to balance the number of moles or molecules reacting and forming.

Combination Reaction

A reaction in which two or more chemical reactants unite to produce a single product.

Decomposition Reaction

A reaction in which a single compound breaks down into two or more simpler chemical substances.

Single-Replacement Reaction

A chemical reaction in which one individual element displaces another element from a compound.

Double-Replacement Reaction

A chemical reaction in which the ions of two reacting compounds exchange partners to generate two entirely new compounds.

Combustion Reaction

A chemical reaction involving rapid oxidation of a substance by oxygen gas, releasing energy in the form of light and heat.

Law of Conservation of Mass

The scientific principle stating that mass is neither created nor destroyed during a chemical process, requiring balanced equations with equal atom counts on both sides.

Forms of Matter Notations (s, l, g, aq)

State symbols placed in parentheses in chemical equations indicating the physical state: solid ($s$), liquid ($l$), gas ($g$), or aqueous solution dissolved in water ($aq$).

Limiting Reactant (Limiting Agent)

The reactant that is completely consumed first in a reaction, thereby capping the theoretical maximum yield of products that can be formed.

Percent Yield

The mathematical ratio of the experimentally obtained actual yield to the calculated theoretical yield, expressed as a percentage: $\frac{\text{Actual Yield}}{\text{Theoretical Yield}} \times 100\%$.

CHEM 108 Exam 2 Format

An examination consisting of 25 multiple-choice questions assessing designated review topics from Chapters 2, 3, 4, 5, and 6.