Chemistry

A chemical reaction involving proton transfer between an acid and a base, or electron-pair donation and acceptance under the broader Lewis definition.

Activation energy quantifies the temperature dependence of a reaction rate constant and is commonly interpreted as an energy barrier to chemical transformation.

An activity coefficient is a dimensionless factor that expresses how a component’s thermodynamic activity differs from its normalized concentration or mole fraction.

Amount of substance is an SI base quantity measuring the number of specified elementary entities in a system, expressed in moles.

Bond order is a numerical description of the multiplicity or degree of bonding between two atoms, defined differently in structural and quantum-chemical models.

Carbon dioxide is a molecular compound central to photosynthesis, the carbon cycle, industrial processes, and Earth’s greenhouse effect.

A chemical equation symbolically represents a reaction, identifying its reactants and products and expressing their relative quantities through balanced coefficients.

Chemical equilibrium is a dynamic state in which opposing reactions balance, leaving the overall composition unchanged under fixed conditions.

Chemical kinetics studies reaction rates, their dependence on physical and chemical conditions, and the mechanisms through which reactions proceed.

A covalent bond is a chemical bond involving shared electron density between atoms, responsible for the structure of molecules and many extended solids.

Distillation separates mixture components through vaporization and condensation, exploiting differences in their distribution between liquid and vapor phases.

A system of electrodes and electrolytes that enables electrical energy conversion, electrically driven chemical reactions, or electrochemical measurement.

An electrode is a conducting component that connects an electrical circuit to an electrochemical medium, enabling charge transfer, measurement, or storage.

Electrolysis uses electrical energy to drive chemical reactions, enabling metal production, surface coating, chemical manufacture, and hydrogen generation.

A substance or medium that conducts electric current through mobile ions, including solutions, molten salts, and certain solids.

Electron configuration describes how electrons occupy orbitals in atoms, ions, and molecules, providing a framework for understanding chemical periodicity and electronic states.

An equilibrium constant specifies the relationship between reactant and product activities at chemical equilibrium for a defined reaction and temperature.

Glucose is a six-carbon simple sugar that serves as a major biological fuel and a building block of larger carbohydrates.

A glycosidic bond connects a sugar’s anomeric carbon to another group, determining the structure and properties of carbohydrates and many other biomolecules.

Graphite is a layered crystalline form of carbon whose conductivity, lubricity, and thermal resistance support numerous industrial applications.

A hydrogen bond is a directional attractive interaction involving a bonded hydrogen atom, important in water, biological structures, and molecular assembly.

A Lewis structure represents valence electrons, covalent bonds, lone pairs, and formal charges in a molecule or ion.

Molar concentration expresses the amount of a specified constituent per unit volume of a solution or mixture.

Molar mass is the mass per unit amount of substance, linking measurable sample masses to quantities of specified chemical entities.

Molecular orbital theory describes molecular electronic structure using orbitals that can extend across several atoms, explaining bonding, magnetism, and aspects of chemical reactivity.

The Nernst equation relates equilibrium electrochemical potentials to temperature and chemical activities, connecting reaction thermodynamics with cell voltages and ionic equilibrium across membranes.

Oxidation state is a formal electron-counting value assigned to an atom to describe its degree of oxidation and track redox changes.

A chemical reaction in which oxidation states change through coupled oxidation and reduction processes.

Oxygen is the chemical element with atomic number 8, a major constituent of air, water, and rocks, and an essential participant in aerobic respiration and combustion.

pH is a logarithmic measure of hydrogen-ion activity used to describe the acidity or basicity of a solution.

A reaction mechanism describes how reactants become products through elementary chemical events, including bond changes, intermediates, transition states, and the factors governing reaction rates.

A solvent is a substance that serves as the dissolving medium of a solution, with properties that influence solubility, chemical reactions, separation processes, and environmental impacts.

Stoichiometry describes the quantitative relationships between reactants and products in chemical reactions.