Free AP Chemistry Flashcards

Import this deck directly into the Stacked app

All 30 Cards

Atom

Smallest unit of an element; consists of protons, neutrons (nucleus) and electrons (orbitals)

Atomic Number

Number of protons in an atom; defines the element; equals electrons in neutral atom

Mass Number

Protons + neutrons; isotopes have same atomic number but different mass numbers

Electron Configuration

Distribution of electrons in orbitals; follows Aufbau principle, Hund's rule, Pauli exclusion

Ionic Bond

Transfer of electrons between metals and nonmetals; creates cations (+) and anions (-)

Covalent Bond

Sharing of electron pairs between nonmetals; single, double, or triple bonds

Electronegativity

Atom's ability to attract shared electrons; increases across a period, decreases down a group

Lewis Dot Structure

Diagram showing valence electrons as dots; used to predict bonding and molecular shape

VSEPR Theory

Valence Shell Electron Pair Repulsion; predicts molecular geometry based on electron pairs

Mole

6.022 × 10²³ particles (Avogadro's number); bridge between atomic and macroscopic scale

Molarity

Concentration = moles of solute / liters of solution; units: mol/L or M

Ideal Gas Law

PV = nRT; P = pressure, V = volume, n = moles, R = gas constant, T = temperature (K)

Stoichiometry

Using balanced equations to calculate quantities of reactants and products; mole ratios

Limiting Reagent

Reactant completely consumed first; determines maximum amount of product formed

Exothermic Reaction

Releases energy/heat to surroundings; ΔH is negative; feels hot

Endothermic Reaction

Absorbs energy/heat from surroundings; ΔH is positive; feels cold

Enthalpy (ΔH)

Heat change at constant pressure; negative = exothermic, positive = endothermic

Entropy (ΔS)

Measure of disorder/randomness; tends to increase; gases > liquids > solids

Gibbs Free Energy

ΔG = ΔH - TΔS; negative ΔG = spontaneous reaction; positive ΔG = non-spontaneous

Le Chatelier's Principle

If a system at equilibrium is disturbed, it shifts to counteract the change

Equilibrium Constant (K)

Ratio of products to reactants at equilibrium; K > 1 favors products; K < 1 favors reactants

Acids and Bases (Brønsted)

Acid: proton (H⁺) donor; Base: proton acceptor; conjugate acid-base pairs

pH Scale

pH = -log[H⁺]; 0-14; 7 neutral; < 7 acidic; > 7 basic; each unit = 10x change

Oxidation-Reduction (Redox)

Oxidation: loss of electrons (OIL); Reduction: gain of electrons (RIG); occur together

Oxidation Number

Charge an atom would have if all bonds were ionic; tracks electron transfer

Periodic Trends

Atomic radius: increases down/left; Ionization energy: increases up/right; Electronegativity: increases up/right

Intermolecular Forces

London dispersion (weakest) < dipole-dipole < hydrogen bonding (strongest); affect boiling points

Solubility Rules

Like dissolves like; polar dissolves polar, nonpolar dissolves nonpolar; NaCl dissolves in water

Reaction Rate

Speed of a reaction; affected by temperature, concentration, surface area, catalysts

Catalyst

Speeds up reaction without being consumed; lowers activation energy; enzymes are biological catalysts

Study this deck on the go with Stacked — the AI-powered flashcard app.

Get Stacked Free →