HESI A2 Chemistry Questions & Answers Updated 2026/2027 – HESI Chemistry Exam Review, Atomic Structure, Periodic Table, Chemical Reactions, Stoichiometry, Bonding, Acids & Bases, Oxidation-Reduction, Radioactivity, Biochemistry – Instant Download

Prepare more effectively for the HESI A2 Chemistry section with this comprehensive, exam-focused study resource covering essential chemistry concepts commonly reviewed in introductory and health-science chemistry preparation. This HESI A2 Chemistry resource is designed for students who need a focused review of atomic structure, the periodic table, chemical reactions, solutions, chemical bonding, stoichiometry, oxidation-reduction reactions, acids and bases, nuclear chemistry, radioactivity, isotopes, half-life, and introductory biochemistry. Whether you are preparing for the HESI Admission Assessment (HESI A2), nursing school admission, allied health programs, health science coursework, or an introductory college chemistry course, this resource provides a convenient way to review important terminology, concepts, definitions, relationships, and chemistry fundamentals. ### HESI A2 CHEMISTRY TOPICS COVERED **Atomic Structure and the Atom** * Atomic structure * Nucleus * Protons * Neutrons * Electrons * Electron clouds * Energy levels * Electron shells * Atomic number * Atomic mass * Isotopes * Ionic states * Cations * Anions * Charged atoms * Nuclear structure Review the fundamental structure of atoms, including the role of protons, neutrons, and electrons, how atomic number identifies an element, how isotopes differ, and how atoms become electrically charged. ### Periodic Table and Element Groups Study essential periodic table concepts including: * Periods * Groups * Group 1A * Group 2A * Alkali metals * Alkaline earth metals * Halogens * Noble gases * Valence electrons * Element properties * Ionic charges * Electron configurations The resource includes important group classifications and commonly tested relationships between an element's periodic-table position, valence electrons, and chemical behavior. ### Chemical Reactions Review the fundamentals of chemical reactions, including: * Reactants * Products * Chemical equations * Conservation of mass * Balanced equations * Equilibrium * Reaction rates * Chemical reaction terminology * Reaction mechanisms * Activation energy Understand why chemical equations must be balanced and how the law of conservation of mass applies to chemical reactions. ### Reaction Rates Important factors affecting reaction rates include: * Temperature * Concentration * Surface area * Catalysts * Kinetic energy * Particle collisions * Activation energy Review how increasing temperature, increasing concentration, increasing surface area, and adding catalysts can influence chemical reaction rates. ### Types of Chemical Reactions Study major reaction categories including: * Synthesis reactions * Decomposition reactions * Combustion reactions * Single-replacement reactions * Double-replacement reactions * Ionic compounds * Hydrocarbons * Carbon dioxide * Water * Reaction products * Reactant relationships Review common reaction patterns and understand how substances are rearranged during different types of chemical reactions. ### Solutions and Mixtures The resource also covers: * Solutions * Homogeneous mixtures * Solutes * Solvents * Compounds * Alloys * Amalgams * Emulsions * Metals * Copper and tin * Mercury Understand the difference between solute and solvent, how solutions are formed, and how alloys, amalgams, and emulsions are classified. ### Chemical Bonding Review important bonding concepts including: * Chemical bonds * Ionic bonding * Covalent bonding * Ionic compounds * Cations * Anions * Electron sharing * Nonpolar covalent bonds * Polar covalent bonds * Electronegativity * Metals and nonmetals Understand the difference between ionic and covalent bonding and how electrons are transferred or shared between atoms. ### Intermolecular Forces Important intermolecular-force concepts include: * Hydrogen bonding * Dipole-dipole interactions * Dispersion forces * London dispersion forces * Molecular polarity * Dipoles * Electronegativity * Hydrogen * Fluorine * Oxygen * Nitrogen Review how intermolecular attractions influence molecules and how hydrogen bonding, dipole-dipole interactions, and dispersion forces differ. ### Stoichiometry and Balancing Equations Review foundational stoichiometry topics such as: * Stoichiometry * Chemical coefficients * Balancing equations * Conservation of mass * Chemical formulas * Polyatomic ions * Diatomic molecules * Reaction ratios * Reactants and products * Quantitative relationships The material includes rules for balancing chemical equations and understanding the numerical relationships between substances participating in chemical reactions. ### Oxidation-Reduction Reactions Study: * Oxidation * Reduction * Electron transfer * Oxidizing agents * Reducing agents * Oxidation numbers * Oxidation states * Electron loss * Electron gain * Redox reactions Remember the core relationship: **Oxidation = loss of electrons** **Reduction = gain of electrons** Review oxidation-state rules and common oxidation-number patterns for elements and compounds. ### Oxidation State Rules The resource includes important oxidation-state concepts involving: * Group 1A metals * Group 2A metals * Hydrogen * Oxygen * Fluorine * Halogens * Monatomic ions * Peroxides * Neutral compounds * Polyatomic ions * Diatomic elements These concepts are useful when determining which species has been oxidized or reduced during a redox reaction. ### Acids and Bases Review essential acid-base chemistry: * Acids * Bases * Proton donors * Hydrogen ions * Hydronium * Hydroxide * pH * Acidity * Alkalinity * Neutral solutions * Litmus paper * Acid-base reactions * Neutralization Important pH concepts include the relationship between acidic, neutral, and basic solutions and the use of litmus indicators. ### pH Scale Review: * pH scale * Acidic solutions * Basic solutions * Neutral solutions * pH 7 * Hydrogen-ion concentration * Acidity * Alkalinity The resource helps reinforce the basic chemistry concepts needed to recognize whether a solution is acidic, neutral, or basic. ### Nuclear Chemistry and Radioactivity Study introductory nuclear chemistry concepts including: * Nuclear reactions * Chemical reactions * Stable nuclei * Unstable nuclei * Radioactivity * Radiation * Radioactive decay * Isotopes * Half-life * Nuclear stability Understand the difference between chemical and nuclear reactions and how unstable nuclei release energy or particles. ### Types of Radiation Review the three major types of radioactive emissions: * Alpha radiation * Beta radiation * Gamma radiation * Helium nuclei * High-energy particles * Electromagnetic radiation * Penetrating radiation * Radiation shielding * Lead shielding * Aluminum shielding Understand the differences in particle composition, charge, mass, and penetrating ability among alpha, beta, and gamma radiation. ### Isotopes and Half-Life Important concepts include: * Isotopes * Radioactive isotopes * Stable isotopes * Unstable nuclei * Radioactive decay * Half-life * Isotope notation * Nuclear stability Review how radioactive isotopes decay over time and what the term half-life means in nuclear chemistry. ### Introductory Biochemistry The resource also introduces: * Biochemistry * Chemistry of living organisms * Biological molecules * Sugars * Starches * Energy storage * Energy sources * Carbohydrates These foundational concepts can help connect general chemistry principles to health sciences and biological systems. ### WHY THIS HESI A2 CHEMISTRY RESOURCE CAN HELP Use this resource to review important chemistry terminology and concepts in a concentrated format rather than searching through multiple disconnected study materials. It is useful for: * HESI A2 Chemistry preparation * HESI Admission Assessment review * Nursing school entrance exam preparation * Allied health admission preparation * Health science students * Biology and chemistry students * Introductory chemistry review * Chemistry terminology review * Last-minute chemistry revision * Exam-focused study * Chemistry concept reinforcement * Atomic structure review * Chemical reaction review * Acid-base review * Nuclear chemistry review * Stoichiometry review * Chemical bonding review ### KEY CONCEPTS TO REVIEW Atomic Structure • Protons • Neutrons • Electrons • Electron Clouds • Energy Levels • Atomic Number • Atomic Mass • Isotopes • Cations • Anions • Periodic Table • Groups • Periods • Noble Gases • Halogens • Chemical Reactions • Reactants • Products • Equilibrium • Reaction Rates • Catalysts • Solutions • Solutes • Solvents • Compounds • Alloys • Emulsions • Ionic Bonds • Covalent Bonds • Intermolecular Forces • Hydrogen Bonds • Dipole-Dipole Forces • Dispersion Forces • Stoichiometry • Balancing Equations • Oxidation • Reduction • Oxidation States • Acids • Bases • pH • Hydronium • Hydroxide • Radioactivity • Alpha Radiation • Beta Radiation • Gamma Radiation • Isotopes • Half-Life • Biochemistry • Carbohydrates This resource is intended as an independent study aid and is not an official publication of HESI, Elsevier, Evolve, Louisiana State University, or any nursing/health-science program. It does not guarantee a particular score or reproduce a live examination. **Study smarter, review the core chemistry concepts, and strengthen your HESI A2 Chemistry preparation with one convenient exam-focused resource.**