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volatility
Chemistry
1
A material quality which describes how readily a substance vaporizes. At a given temperature and pressure, a substance with high volatility is more likely to exist as a gas, while a substance with low volatility is more likely to exist as a liquid or solid; equivalently, less volatile substances will more readily condense from a gaseous state than highly volatile ones.
volt
Chemistry
1
A derived unit of electric potential, electric potential difference, and electromotive force, defined as one joule of work per coulomb.
v
Chemistry
1
A derived unit of electric potential, electric potential difference, and electromotive force, defined as one joule of work per coulomb.
voltmeter
Chemistry
1
An instrument that measures electrical cell potential.
volume
Chemistry
1
The quantity of three-dimensional space enclosed by a closed surface, or the space that a substance (solid, liquid, gas, or plasma) or shape occupies or contains. The SI unit for volume is the cubic metre (m3).
volumetric analysis
Chemistry
1
See titration.
watch glass
Chemistry
1
A circular, concave piece of glass commonly used in chemistry laboratories as a working surface for various purposes, such as evaporating liquids, holding solids while they are being weighed, heating small amounts of a substance, or as a cover for a beaker.
water
Chemistry
1
A polar inorganic compound with the chemical formula H2O that is a tasteless, odorless, and generally colorless liquid at standard temperature and pressure, though it also occurs naturally as a solid and a gas at the Earth's surface. It is the most abundant substance on Earth and therefore an integral component of virtually all chemical and biological systems. Water is often described as the "universal solvent" for its inherent ability to dissolve many substances.
water of crystallization
Chemistry
1
Water molecules that are present inside crystals. Upon crystallization from water or aqueous solutions, many compounds incorporate water in the interstices of their crystalline frameworks; the water molecules are typically present in a stoichiometric ratio and may interact to varying degrees with the atoms of the crystal.
wave function
Chemistry
1
A mathematical function describing the position of an electron within a three-dimensional space.
weak acid
Chemistry
1
An acid that only partially dissociates when dissolved in a solvent because, according to the reaction HA ↽ − − ⇀ H + + A − {\ce {HA <=> H+ + A-}}} , equilibrium is reached while the concentration of the undissociated species HA {\ce {HA}}} is still significant; an example is acetic acid (CH3COOH). Contrast strong acid.
wet chemistry
Chemistry
1
A form of analytical chemistry which uses classical laboratory methods such as simple observation and elementary chemical tests to study chemicals and chemical reactions, i.e. without the use of sophisticated instruments or automated or computerized analysis. It is often used in schools to teach the principles of chemistry to students.
work-up
Chemistry
1
The series of manipulations required to isolate and purify the desired product or products of a chemical reaction.
x-ray
Chemistry
1
A form of ionizing, electromagnetic radiation between gamma and ultraviolet rays in the electromagnetic spectrum.
x-ray diffraction
Chemistry
1
A laboratory method for establishing the structure of a crystalline solid by directing single wavelength X-rays at the solid and analyzing the resulting diffraction pattern.
x-ray photoelectron spectroscopy
Chemistry
1
A spectroscopic technique used to measure the chemical composition of a material.
yield
Chemistry
1
The quantifiable amount of product produced during a chemical reaction.
zone melting
Chemistry
1
Any of several methods of purifying crystalline solids which involve applying heat to a small region of a larger solid (particularly a metal ingot) until localized melting occurs, creating a molten zone which is then slowly moved along the surface to other parts of the solid by moving the target of the heating element. As it moves, the forward edge of the molten zone continuously melts new areas of impure solid, while leaving a path of purer solid behind it as previously melted areas are cooled and resolidified; because the molten liquid phase can hold a higher concentration of impurities than the solid phase, the impurities of melted areas tend to concentrate in the molten zone and be carried along as it moves, leaving behind regions with fewer impurities. The process is commonly used in the refinement of high-purity metalloids for use in semiconductors.
zinc
Chemistry
1
A metallic chemical element with atomic number 30 and symbol Zn.
zwitterion
Chemistry
1
Any molecule that contains an internal polarity by virtue of having an equal number of positively charged and negatively charged functional groups.
catalyst
Chemistry
1
A substance that increases the rate of a chemical reaction without being consumed in the process.
molecule
Chemistry
1
A group of atoms bonded together, representing the smallest unit of a chemical compound.
oxidation
Chemistry
1
The process in which an atom or molecule loses electrons, often associated with the addition of oxygen or the removal of hydrogen.
isotope
Chemistry
1
Atoms of the same element with the same number of protons but a different number of neutrons.
covalent bond
Chemistry
1
A type of chemical bond in which two atoms share one or more pairs of electrons.
periodic table
Chemistry
1
A tabular arrangement of chemical elements, organized by atomic number, electron configuration, and recurring chemical properties.
avogadro's number
Chemistry
1
The number of particles in one mole of a substance, approximately 6.022 × 10²³.
electrolysis
Chemistry
1
The chemical decomposition produced by passing an electric current through a liquid or solution.
alloy
Chemistry
1
A mixture of two or more metals, or a metal and another element.
reactant
Chemistry
1
A substance that takes part in and undergoes change during a chemical reaction.
solubility
Chemistry
1
The ability of a substance to dissolve in a solvent to form a homogeneous solution.
ionic bond
Chemistry
1
A type of chemical bond formed by the electrostatic attraction between oppositely charged ions.
polymer
Chemistry
1
A large molecule composed of repeating structural units, typically connected by covalent bonds.
acid
Chemistry
1
A substance that increases the concentration of hydrogen ions in a solution.
base
Chemistry
1
A substance that increases the concentration of hydroxide ions in a solution.
redox reaction
Chemistry
1
A chemical reaction in which the oxidation states of atoms are changed, involving the transfer of electrons.
chemical equilibrium
Chemistry
1
The state in which the forward and reverse reactions occur at the same rate.
sublimation
Chemistry
1
The process by which a solid changes directly into a gas without becoming a liquid.
hydrogen bond
Chemistry
1
A weak bond between a hydrogen atom and another electronegative atom.
endothermic reaction
Chemistry
1
A chemical reaction that absorbs heat energy from its surroundings.
exothermic reaction
Chemistry
1
A chemical reaction that releases heat energy to its surroundings.
molarity
Chemistry
1
A unit of concentration, defined as the number of moles of solute per liter of solution.
electronegativity
Chemistry
1
The tendency of an atom to attract electrons in a chemical bond.
radioactivity
Chemistry
1
The emission of particles or energy from the nucleus of an unstable atom.
crystallization
Chemistry
1
A process of forming solid crystals from a liquid or gas phase, often used in chemical manufacturing.
van der waals forces
Chemistry
1
Weak attractive forces between molecules due to temporary dipoles.
chelation
Chemistry
1
The formation of a complex where a single molecule binds to a metal ion at multiple points.
isomer
Chemistry
1
Compounds with the same molecular formula but different structural arrangements of atoms.
zeolite
Chemistry
1
A microporous mineral used as a catalyst or molecular sieve.
electrolyte
Chemistry
1
A substance that produces ions when dissolved in water, allowing the conduction of electricity.
titration
Chemistry
1
A laboratory method of determining the concentration of a substance by adding a reagent of known concentration.
kinetics
Chemistry
1
The study of the rates of chemical reactions.
le chatelier's principle
Chemistry
1
The principle stating that if a system at equilibrium is disturbed, the system will shift to counteract the disturbance.
ligand
Chemistry
1
An ion or molecule that binds to a central metal atom to form a complex.
radical
Chemistry
1
An atom, molecule, or ion with unpaired valence electrons.
aromaticity
Chemistry
1
A property of cyclic molecules with conjugated π-electron systems that leads to unusual stability.
hydrophobic interaction
Chemistry
1
The tendency of nonpolar substances to aggregate in aqueous solutions to minimize disruption of water's hydrogen bonding.
spectroscopy
Chemistry
1
A technique used to measure and analyze the interaction between matter and electromagnetic radiation.
kieselguhr
Chemistry
1
A form of diatomaceous earth used in filtration and as an abrasive.
hydrolysis
Chemistry
1
The chemical breakdown of a compound due to reaction with water.
polymorphism
Chemistry
1
The ability of a material to exist in more than one form or crystal structure.
mass spectrometry
Chemistry
1
An analytical technique used to measure the mass-to-charge ratio of ions.
nanoparticle
Chemistry
1
A microscopic particle with dimensions on the nanometer scale, often exhibiting unique properties compared to bulk material.
supramolecular chemistry
Chemistry
1
The study of non-covalent interactions between molecules to form larger complexes.
fischer-tropsch synthesis
Chemistry
1
A method for producing liquid hydrocarbons from carbon monoxide and hydrogen, used in fuel production.
x-ray crystallography
Chemistry
1
A technique for determining the atomic and molecular structure of a crystal by analyzing the diffraction of X-rays.
molecular orbital theory
Chemistry
1
A theory in chemistry that describes the behavior of electrons in molecules using orbitals that span the entire molecule.
polyelectrolyte
Chemistry
1
A polymer whose repeating units bear an electrolyte group, capable of dissociating in solution to form charged ions.
organocatalysis
Chemistry
1
The use of organic molecules to catalyze chemical reactions, providing an alternative to metal catalysts.
pyrimidine
Chemistry
1
A heterocyclic organic compound that is a component of nucleic acids like DNA and RNA.
kerr effect
Chemistry
1
The change in the refractive index of a material due to an applied electric field, a phenomenon observed in nonlinear optics.
atom
Chemistry
1
The smallest unit of matter, composed of protons, neutrons, and electrons.
catalysis
Chemistry
1
The process by which the rate of a chemical reaction is increased by a catalyst, which remains unchanged after the reaction.
acid-base reaction
Chemistry
1
A chemical reaction that involves the transfer of protons (H⁺) between reactants.
enzyme
Chemistry
1
A protein that acts as a catalyst in biochemical reactions.
alkali metals
Chemistry
1
Group 1 elements of the periodic table, known for their high reactivity, including lithium, sodium, and potassium.
transition metals
Chemistry
1
Elements found in the middle of the periodic table that often form colored compounds and have variable oxidation states.
lanthanides
Chemistry
1
A series of 15 chemical elements in the periodic table from lanthanum to lutetium, known for their magnetic and optical properties.
actinides
Chemistry
1
A series of elements in the periodic table from actinium to lawrencium, many of which are radioactive.
amino acid
Chemistry
1
Organic compounds that combine to form proteins and play key roles in cellular functions.
covalent bonding
Chemistry
1
A chemical bond formed when two atoms share electrons to achieve a stable electron configuration.
polyatomic ion
Chemistry
1
An ion composed of two or more atoms bonded together that carry a charge.
vsepr theory
Chemistry
1
A model used to predict the shape of molecules based on the repulsion between electron pairs around a central atom.
molecular orbital
Chemistry
1
A region in a molecule where electrons are likely to be found, formed by the overlap of atomic orbitals.
titration curve
Chemistry
1
A graph of the pH of a solution during a titration, used to determine the concentration of an unknown solution.
catalytic converter
Chemistry
1
A device used in vehicles to reduce toxic gases and pollutants from an internal combustion engine.
zwitterion
Chemistry
1
A molecule that has both a positive and a negative charge, but is overall electrically neutral.
levorotatory
Chemistry
1
A compound that rotates the plane of polarized light counterclockwise.
dextrorotatory
Chemistry
1
A compound that rotates the plane of polarized light clockwise.
solubility product
Chemistry
1
The equilibrium constant for the dissolution of a sparingly soluble ionic compound.
nucleophilic substitution
Chemistry
1
A reaction in which a nucleophile replaces a leaving group in a molecule.
organometallic compound
Chemistry
1
A compound containing a metal atom bonded to a carbon atom of an organic group.
stoichiometry
Chemistry
1
The calculation of reactants and products in chemical reactions, based on the conservation of mass and the mole concept.
michael addition
Chemistry
1
A nucleophilic addition reaction in which a nucleophile adds to an α,β-unsaturated carbonyl compound.
hydrocarbon
Chemistry
1
A compound made entirely of hydrogen and carbon atoms, such as alkanes, alkenes, and alkynes.
functional group
Chemistry
1
A specific group of atoms within a molecule that is responsible for its chemical reactions and properties.
aromatic compounds
Chemistry
1
Organic compounds containing benzene rings, often with distinct odors.
alkane
Chemistry
1
A saturated hydrocarbon with single bonds between carbon atoms, such as methane and ethane.
alkene
Chemistry
1
A hydrocarbon with at least one double bond between carbon atoms, such as ethene (ethylene).
alkyne
Chemistry
1
A hydrocarbon with at least one triple bond between carbon atoms, such as ethyne (acetylene).