Glossary of chemistry terms

Updated on Dec 12, 2024

Edit

Comment

This page is a glossary of chemistry terms. Chemistry has an extensive vocabulary and a significant amount of jargon. This is a list of chemical terms, including laboratory tools, glassware, and equipment. Chemistry itself is a physical science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions.

A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
References

Note: All periodic table references refer to the IUPAC Style of the Periodic Table

A

absolute zero – a theoretical condition concerning a system at zero Kelvin where a system does not emit or absorb energy (all atoms are at rest)

absorbance -

accuracy – how close a value is to the actual or true value; also see precision

acid – a compound that, when dissolved in water, gives a pH of less than 7.0 or a compound that donates a hydrogen ion

acid anhydride – a compound with two acyl groups bound to a single oxygen atom

acid dissociation constant – an equilibrium constant for the dissociation of a weak acid

actinides – the fifteen chemical elements that are between actinium (89) and lawrencium (103)

activated complex – a structure that forms because of a collision between molecules while new bonds are formed

activation energy – the minimum energy that must be input to a chemical system

activity series

actual yield

addition reaction – within organic chemistry, when two or more molecules combine to make a larger one

adhesion -

aeration – the mixing of air into a liquid or solid

alcohol -

aldehyde -

alkali metals – the metals of Group 1 on the periodic table

alkaline earth metals – the metals of Group 2 on the periodic table

alkane -

alkene -

alkyl group -

alkyne -

allomer – a substance that has different composition than another, but has the same crystalline structure

allotropy – elements that can have different structures (and therefore different forms), such as Carbon (diamonds, graphite, and fullerene)

amplitude – the maximum distance that the particles of the medium carrying the wave move away from their rest position

anion – negatively charge ions

anode – the positive side of a dry cell battery or a cell

aromaticity – chemical property of conjugated rings that results in unusual stability. See also benzene.

atom – a chemical element in its smallest form, and is made up of neutrons and protons within the nucleus and electrons circling the nucleus

atomic mass unit

atomic number – the number representing an element which corresponds with the number of protons within the nucleus

atomic orbital – the region where the electron of the atom may be found

atomic radius

average atomic mass

Avogadro's law

Avogadro's number – is the number of particles in a mole of a substance now let's talk of compound

B

barometer – a device used to measure the pressure in the atmosphere

base – a substance that accepts a proton and has a high pH; a common example is sodium hydroxide (NaOH)

base anhydride – oxides of group I and II metal elements

beat – a slow oscillation in amplitude of a complex wave

Beer-Lambert law -

biochemistry – the chemistry of organisms

Bohr model -

boiling – the phase transition of liquid vaporizing

boiling point – the temperature in which the substance starts to boil

boiling-point elevation – the process where the boiling point is elevated by adding a substance

bond – the attraction and repulsion between atoms and molecules that is a cornerstone of chemistry

Boyle's law – for a given mass of gas at constant temperature, the volume varies inversely with the pressure

Bragg's law -

Brønsted-Lowrey acid – A chemical species that donates a proton

Brønsted–Lowry acid–base reaction -

Brønsted-Lowrey base – A chemical species that accepts a proton

buckminsterfullerene -

buffered solution – An aqueous solution consisting of a weak acid and its conjugate base or a weak base and its conjugate acid that resists changes in pH when strong acids or bases are added

bumping -

burette (also buret) – glassware used to dispense specific amounts of liquid when precision is necessary (e.g. titration and resource dependent reactions)

C

calorimeter -

catalyst – a chemical (element or compound) used to speed up a reaction, but is regenerated at the end of the reaction.

cation – positively charged ion

centrifugation -

centrifuge – equipment used to separate substances based on density by rotating the tubes around a centred axis

cell potential – the force in a galvanic cell that pulls electron through reducing agent to oxidizing agent

chain reaction -

Charles's law -

chelation -

chemical formula -

chemical law – certain rules that pertain to the laws of nature and chemistry – examples

chemical reaction – the change of one or more substances into another or multiple substances

closed system -

colligative properties -

colloid – mixture of evenly dispersed substances, such as many milks

combustion – an exothermic reaction between an oxidant and fuel with heat and often light

compression – an area in a longitudinal wave where the particles are closer and pushed in

compound – a substance that is made up of two or more chemically bonded elements

condensation – the phase change from gas to liquid

conductor – material that allows electric flow more freely

conjugate acid -

conjugated system -

cooling curve -

covalent bond – chemical bond that involves sharing electrons

crest – the highest point in a wave

crystal – a solid that is packed with ions, molecules or atoms in an orderly fashion

cuvette – glassware used in spectroscopic experiments. It is usually made of plastic, glass or quartz and should be as clean and clear as possible

D

Dalton's law of partial pressures -

deionization – the removal of ions, and in water's case mineral ions such as sodium, iron and calcium

deliquescence – substances that absorb water from the atmosphere to form liquid solutions

density – The amount of mass per unit volume. d = m/V

deposition – settling of particles within a solution or mixture

diffusion -

dipolar bond -

dipole – electric or magnetic separation of charge

dipole moment – the polarity of a polar covalent bond

dissolution or solvation – the spread of ions in a monosaccharide

double bond – sharing of two pairs of electrons (in a covalent bond)

diatomic-consistent of two atoms

E

earth metal – see alkaline earth metal

electrolyte – a solution that conducts a certain amount of current and can be split categorically as weak and strong electrolytes

electrochemical cell – using a chemical reaction's current, electromotive force is made

electromagnetic radiation – a type of wave that can go through vacuums as well as material and classified as a self-propagating wave

electromagnetism – fields that have electric charge and electric properties that change the way that particles move and interact

electromotive force – a device that gains energy as electric charges pass through it

electron – a subatomic particle with a net charge that is negative

electron shells – an orbital around the atom's nucleus that has a fixed number electrons (usually two or eight)

electric charge – a measured property (coulombs) that determine electromagnetic interaction

element – an atom that is defined by its atomic number

energy – A system's ability to do work

enthalpy – measure of the total energy of a thermodynamic system (usually symbolized as H)

entropy – the amount of energy not available for work in a closed thermodynamic system (usually symbolized as S)

enzyme – a protein that speeds up (catalyses) a reaction

Empirical Formula – also called the simplest formula, gives the simplest whole -number ratio of atoms of each element present in a compound.

eppendorf tube – generalized and trademarked term used for a type of tube; see microcentrifuge

exothermic process -

extrinsic property -

F

freezing – phase transition from liquid to solid

Faraday constant – a unit of electrical charge widely used in electrochemistry and equal to ~ 96,500 coulombs.

It represents 1 mol of electrons, or the Avogadro number of electrons: 6.022 × 10²³ electrons. F = 96 485.339 9(24) C/mol

Faraday's law of electrolysis – a two part law that Michael Faraday published about electrolysis

the mass of a substance altered at an electrode during electrolysis is directly proportional to the quantity of electricity transferred at that electrode

the mass of an elemental material altered at an electrode is directly proportional to the element's equivalent weight.

Fick's laws of diffusion -

frequency – number of cycles per unit of time. Unit: 1 hertz = 1 cycle per 1 second

G

Galvanic cell – battery made up of electrochemical with two different metals connected by salt bridge

gas – particles that fill their container though have no definite shape or volume

Gay-Lussac's Law – The expression Gay-Lussac's law is used for each of the two relationships named after the French chemist Joseph Louis Gay-Lussac and which concern the properties of gases, though it is more usually applied to his law of combining volumes

geochemistry – the chemistry of and chemical composition of the Earth

Gibbs energy – value that indicates the spontaneity of a reaction (usually symbolized as G)

"gram-atom"-one gram atom of an element means collection of 6.023X10^23 atoms

group – the elements in a column of the periodic table. A family of elements

H

halogens – Group 17 on the Periodic Table and are all non-metals

hadron – a subatomic particle of a type including the baryons and mesons that can take part in the strong interaction

heat – energy transferred from one system to another by thermal interaction

Henry's law -

Hess's law -

Hund's rules -

I

ideal gas -

ideal gas law – the volume of a gas is proportional to the amount of gas and its Kelvin temperature and inversely proportional to its pressure

indicator – a special compound added to solution that changes color depending on the acidity of the solution; different indicators have different colors and effective pH ranges

induced radioactivity – radioactivity caused by bombarding a stable isotope with elemental particles, forming a radioactive isotope

inorganic compound – compounds that do not contain carbon, though there are exceptions (see main article)

inorganic chemistry – a part of chemistry concerned with inorganic compounds

IUPAC – International Union of Pure and Applied Chemistry

insulator – material that resists the flow of electric current

intrinsic property -

ion – a molecule that has gained or lost one or more electrons

ionic bond – electrostatic attraction between oppositely charged ions

ionization -The breaking up of a compound into separate ions.

J

jodium – Latin name of the halogen element iodine

Joule – The SI unit of energy, defined as a newton-meter.

K

kelvin – A unit of measure for temperature based upon an absolute scale.

ketone – an organic compound with a carbonyl group between two carbon atoms

Kinetics – A sub-field of chemistry specializing in reaction rates

Kinetic energy – The energy of an object due to its motion.

L

lanthanides – Elements 57 through 71

lattice – Unique arrangement of atoms or molecules in a crystalline liquid or solid.

Laws of thermodynamics

Lewis acid -

Lewis base -

liquid – A state of matter in which cohesive force is less than or equal to the separating force.

light – Portion of the electromagnetic spectrum which is visible to the naked eye. Also called "visible light."

London dispersion forces – A weak intermolecular force

laws of motion – An object in motion stays in motion; an object at rest stays at rest unless an unbalanced force acts on it.

M

magnetic quantum number -

manometer - Instrument to measure pressure, invented by Evangelista Torricelli in 1643.

mass -

mass concentration -

mass fraction -

metal – Chemical element that is a good conductor of both electricity and heat and forms cations and ionic bonds with non-metals.

melting – The phase change from a solid to a liquid

metalloid – A substance possessing both the properties of metals and non-metals

methylene blue – a heterocyclic aromatic chemical compound with the molecular formula C₁₆H₁₈N₃SCl

microcentrifuge – a small plastic container that is used to store small amounts of liquid

molar attenuation coefficient -

molar mass -

mole – abbreviated mol – a measurement of an amount of substance; a single mole contains approximately 6.022×10²³ units or entities

a mole of water contains 6.022×10²³ H₂O molecules

molecular formula -

molecular orbital – region where an electron can be found in a molecule (as opposed to an atom)

molecular orbital diagram -

molecule – a chemically bonded number of atoms that are electrically neutral

MALIBILITYTemplate:SNDthe ability of a metal to be harmered into different shapes

N

neat – conditions with a liquid reagent or gas performed with no added solvent or cosolvent

neutron – a neutral unit or subatomic particle that has no net charge

neutrino – a particle that can travel at speeds close to the speed of light and are created as a result of radioactive decay

nucleus – the centre of an atom made up of neutrons and protons, with a net positive charge

noble gases – group 18 elements, those whose outer electron shell is filled

non-metal – an element which is not metallic

nuclear – of or pertaining to the atomic nucleus

nuclear magnetic resonance spectroscopy – technique that exploits the magnetic properties of certain nuclei, useful for identifying unknown compounds

number density – a measure of concentration of countable objects (atoms, molecules, etc.) in space; number per volume

O

orbital – may refer to either an atomic orbital or a molecular orbital

organic compound – compounds that contain carbon

organic chemistry – a part of chemistry concerned with organic compounds

organic redox reaction -

oxidation -

oxidation state -

oxidizing agent -

P

pH – the measure of acidity (or basicity) of a solution

plasma – state of matter similar to gas in which a certain portion of the particles are ionized

other metal – metallic elements in the p-block, characterized by having a combination of relatively low melting points (all less than 950 K) and relatively high electronegativity values (all more than 1.6, revised Pauling)

potential energy – energy stored in a body or in a system due to its position in a force field or due to its configuration

precipitate – formation of a solid in a solution or inside another solid during a chemical reaction or by diffusion in a solid

precision – How close the results of multiple experimental trials are. See also accuracy.

photon – a carrier of electromagnetic radiation of all wavelength (such as gamma rays and radio waves)

proton – a positive unit or subatomic particle that has a positive charge

protonation – the addition of a proton (H⁺) to an atom, molecule, or ion

Q

Quantum mechanics – the study of how atoms, molecules, subatomic particles, etc. behave and are structured

quarks – elementary particle and a fundamental constituent of matter

quanta- It is the minimum amount of bundle of energy

R

radiation – energy in the form of waves or subatomic particles when there is a change from high energy to low energy states

radioactive decay – the process of an unstable atomic nucleus losing energy by emitting radiation

Raoult's law -

reactivity series -

reagent -

redox -

reducing agent -

reduction potential -

S

s-block elements – Group 1 and 2 elements (alkali and alkaline metals), which includes Hydrogen and Helium

salts – ionic compounds composed of anions and cations

salt bridge – devices used to connection reduction with oxidation half-cells in an electrochemical cell

saline solution – general term for NaCl in water

Schrödinger equation – quantum state equation which represents the behaviour of an election around an atom

semiconductor – an electrically conductive solid that is between a conductor and an insulator

single bond – sharing of one pair of electrons

sol – a suspension of solid particles in liquid. Artificial examples include sol-gels.

solid – one of the states of matter, where the molecules are packed close together, there is a resistance of movement/deformation and volume change; see Young's modulus

solute – the part of the solution that is mixed into the solvent (NaCl in saline water)

solution – homogeneous mixture made up of multiple substances. It is made up of solutes and solvents.

solvent – the part of the solution that dissolves the solute (H₂O in saline water)

spectrochemistry -

spectroscopy – study of radiation and matter, such as X-ray absorption and emission spectroscopy

speed of light – the speed of anything that has zero rest mass (Energy_rest = mc² where m is the mass and c is the speed of light)

Standard conditions for temperature and pressure or SATP – a standardisation used in order compare experimental results (25 °C and 100.000 kPa)

state of matter – matter having a homogeneous, macroscopic phase; gas, plasma, liquid, and solid are the most well known (in increasing concentration)

structural formula -

sublimation – a phase transition from solid to limewater fuel or gas

subatomic particles – particles that are smaller than an atom; examples are protons, neutrons and electrons

substance – material with definite chemical composition

T

talc – a mineral representing the one on the Mohs Scale and composed of hydrated magnesium silicate with the chemical formula H₂Mg₃(SiO₃)₄ or Mg₃Si₄O₁₀(OH)₂

temperature – the average energy of microscopic motions of particles

theoretical yield – see yield

theory – a model describing the nature of a phenomenon

thermal conductivity – a property of a material to conduct heat (often noted as k )

thermochemistry – the study of absorption/release of heat within a chemical reaction

thermodynamics – the study of the effects of changing temperature, volume or pressure (or work, heat, and energy) on a macroscopic scale

thermodynamic stability – when a system is in its lowest energy state with its environment (equilibrium)

thermometer – device that measures the average energy of a system

titration – the process of titrating one solution with another, also called volumetric analysis

torr – a unit to measure pressure (1 Torr is equivalent to 133.322 Pa or 1.3158×10⁻³ atm)

transition metal – elements that have incomplete d sub-shells, but also may be referred to as the d-block elements

transuranic element – element with atomic number greater than 92; none of the transuranic elements are stable

triple bond – the sharing of three pairs of electrons within a covalent bond (example N₂)

triple point – the place where temperature and pressure of three phases are the same (Water has a special phase diagram)

Tyndall effect – the effect of light scattering by colloidal (mixture where one substance is dispersed evenly through another) or suspended particles

U

UN number – a four digit code used to note hazardous and flammable substances

uncertainty – a characteristic that any measurement that involves estimation of any amount cannot be exactly reproducible

Uncertainty principle – knowing the location of a particle makes the momentum uncertain, while knowing the momentum of a particle makes the location uncertain

unit cell – the smallest repeating unit of a lattice

unit factor – statements used in converting between units

universal or ideal gas constant – proportionality constant in the ideal gas law (0.08206 L·atm/(K·mol))

V

valence electron – the outermost electrons of an atom, which are located in electron shells

Valence bond theory – a theory explaining the chemical bonding within molecules by discussing valencies, the number of chemical bonds formed by an atom

valency – The combining capacity of an element.

van der Waals force – one of the forces (attraction/repulsion) between molecules

van 't Hoff factor – ratio of moles of particles in solution to moles of solute dissolved

vapor – when a substance is below the critical temperature while in the gas phase

vapour pressure – pressure of vapour over a liquid at equilibrium

vaporization – phase change from liquid to gas

viscosity – the resistance of a liquid to flow (oil)

volt – one joule of work per coulomb – the unit of electrical potential transferred

voltmeter – instrument that measures the cell potential

volumetric analysis – see titration

W

water – H₂O – a chemical substance, a major part of cells and Earth, and covalently bonded

wave function – a function describing the electron's position in a three-dimensional space

work – the amount of force over distance and is in terms of joules (energy)

X

X-ray – form of ionizing, electromagnetic radiation, between gamma and UV rays

X-ray diffraction – a method for establishing structures of crystalline solids using singe wavelength X-rays and looking at diffraction pattern

X-ray photoelectron spectroscopy – a spectroscopic technique to measure composition of a material

Y

yield – the amount of product produced during a chemical reaction

Z

zone melting – a way to remove impurities from an element by melting it and slowly travel down an ingot (cast)

Zwitterion – is a chemical compound whose net charge is zero and hence is electrically neutral. But there are some positive and negative charges in it, due to the formal charge, owing to the partial charges of its constituent atoms.

zinc-an element or a metal with symbol Zn

References

Glossary of chemistry terms Wikipedia

(Text) CC BY-SA

Contents

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

References