Physical chemistry

Singlet oxygen is a high energy form of oxygen.

An ionic liquid (IL) is a salt in the liquid state.

Total dissolved solids (TDS) is a measure of the combined content of all inorganic and organic substances contained in a liquid in molecular, ionized or micro-granular (colloidal sol) suspended form.

Calorimetry is the science or act of measuring changes in state variables of a body for the purpose of deriving the heat transfer associated with changes of its state due for example to chemical reactions, physical changes, or phase transitions under specified constraints.

Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface.

Allotropy or allotropism (from Greek ἄλλος (allos), meaning "other", and τρόπος (tropos), meaning "manner, form") is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of these elements.

An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water.

Ionization is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions, often in conjunction with other chemical changes.

In chemistry, Le Chatelier's principle (pronounced /lə ˈʃɑːtlieɪ/), also called Chatelier's principle or "The Equilibrium Law", can be used to predict the effect of a change in conditions on a chemical equilibrium.

In chemistry, pH (/piːˈeɪtʃ/) is a numeric scale used to specify the acidity or basicity of an aqueous solution.

Radiation chemistry is a subdivision of nuclear chemistry which is the study of the chemical effects of radiation on matter; this is very different from radiochemistry as no radioactivity needs to be present in the material which is being chemically changed by the radiation.

A solar cell, or photovoltaic cell (in very early days also termed "solar battery" – a denotation which nowadays has a totally different meaning, see here), is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.

In chemistry, a solution is a homogeneous mixture composed of two or more substances.

Solubility is the property of a solid, liquid, or gaseous chemical substance called solute to dissolve in a solid, liquid, or gaseous solvent.

Standard conditions for temperature and pressure are standard sets of conditions for experimental measurements to be established to allow comparisons to be made between different sets of data.

In physical chemistry, the van der Waals forces (or van der Waals interaction), named after Dutch scientist Johannes Diderik van der Waals, are the residual attractive or repulsive forces between molecules or atomic groups that do not arise from a covalent bond, or ionic bonds.

A carbanion is an anion in which carbon is tervalent (forms three bonds) and bears a formal negative charge in at least one significant mesomeric contributor (resonance form).

Chemical kinetics, also known as reaction kinetics, is the study of rates of chemical processes.

Intermolecular forces (IMFs) are forces of attraction or repulsion which act between neighboring particles (atoms, molecules, or ions).

A phase diagram in physical chemistry, engineering, mineralogy, and materials science is a type of chart used to show conditions (pressure, temperature, volume, etc.) at which thermodynamically distinct phases occur and coexist at equilibrium.

Gibbs' phase rule was proposed by Josiah Willard Gibbs in his landmark paper titled On the Equilibrium of Heterogeneous Substances, published from 1875 to 1878.

In chemistry, saturation (from the Latin word saturare, means to fill) has diverse meanings, all based on the idea of reaching a maximum capacity.

A gel is a solid jelly-like material that can have properties ranging from soft and weak to hard and tough.

In chemistry, absorption is a physical or chemical phenomenon or a process in which atoms, molecules or ions enter some bulk phase – gas, liquid or solid material.

Cryochemistry is the study of chemical interactions at temperatures below −150 °C (−238 °F; 123 K).

An acid dissociation constant, Ka, (also known as acidity constant, or acid-ionization constant) is a quantitative measure of the strength of an acid in solution.

In thermodynamics, a critical point (or critical state) is the end point of a phase equilibrium curve.

Polarography is a subclass of voltammetry where the working electrode is a dropping mercury electrode (DME) or a static mercury drop electrode (SMDE), which are useful for their wide cathodic ranges and renewable surfaces.

In chemical thermodynamics, activity (symbol a) is a measure of the “effective concentration” of a species in a mixture, in the sense that the species' chemical potential depends on the activity of a real solution in the same way that it would depend on concentration for an ideal solution.

The specific weight (also known as the unit weight) is the weight per unit volume of a material.

Magnetochemistry is concerned with the magnetic properties of chemical compounds.

In chemistry, the study of sonochemistry is concerned with understanding the effect of ultrasound in forming acoustic cavitation in liquids, resulting in the initiation or enhancement of the chemical activity in the solution.

Brunauer–Emmett–Teller (BET) theory aims to explain the physical adsorption of gas molecules on a solid surface and serves as the basis for an important analysis technique for the measurement of the specific surface area of a material.

The Goldman–Hodgkin–Katz voltage equation, more commonly known as the Goldman equation, is used in cell membrane physiology to determine the reversal potential across a cell's membrane, taking into account all of the ions that are permeant through that membrane.

Isotopomers or isotopic isomers are isomers with isotopic atoms, having the same number of each isotope of each element but differing in their positions.

This lists the character tables for the more common molecular point groups used in the study of molecular symmetry.

Photoelectrochemical processes are processes in photoelectrochemistry; they usually involve transforming light into other forms of energy.

The dissolution of gases, liquids, or solids into a liquid or other solvent is a process by which these original states become solutes (dissolved components), forming a solution of the gas, liquid, or solid in the original solvent.

Water content or moisture content is the quantity of water contained in a material, such as soil (called soil moisture), rock, ceramics, fruit, or wood.

Conductivity (or specific conductance) of an electrolyte solution is a measure of its ability to conduct electricity.

This article summarizes equations in the theory of electromagnetism.

This article summarizes equations in the theory of gravitation.

In thermodynamics, the volume of a system is an important extensive parameter for describing its thermodynamic state.

Fluorescence correlation spectroscopy (FCS) is a correlation analysis of fluctuation of the fluorescence intensity.