This is a list of physical quantities

Physical quantity

A physical quantity is a physical property of a phenomenon, body, or substance, that can be quantified by measurement.-Definition of a physical quantity:Formally, the International Vocabulary of Metrology, 3rd edition defines quantity as:...

.

The first table lists the base quantities used in the International System of Units

International System of Units

The International System of Units is the modern form of the metric system and is generally a system of units of measurement devised around seven base units and the convenience of the number ten. The older metric system included several groups of units...

 to define the physical dimension of physical quantities for dimensional analysis

Dimensional analysis

In physics and all science, dimensional analysis is a tool to find or check relations among physical quantities by using their dimensions. The dimension of a physical quantity is the combination of the basic physical dimensions which describe it; for example, speed has the dimension length per...

. Note that the angle and solid angle are included in this list but are actually dimensionless quantities. The second table list the other physical quantities.

Note that neither the names nor the symbols used for the physical quantities are international standards. Some quantities are known under several different names such as the magnetic B-field which known as the magnetic flux density, the magnetic induction or simply as the magnetic field depending on the context. Similarly, surface tension can be denoted by either σ, γ or T. The table usually list only one name and symbol.

The final column lists some special properties some of the quantities have such as their scaling behavior (i.e. whether the quantity is intensive or extensive), their transformation properties (i.e. whether the quantity is a scalar

Scalar (mathematics)

In linear algebra, real numbers are called scalars and relate to vectors in a vector space through the operation of scalar multiplication, in which a vector can be multiplied by a number to produce another vector....

, vector or tensor

Tensor

Tensors are geometric objects that describe linear relations between vectors, scalars, and other tensors. Elementary examples include the dot product, the cross product, and linear maps. Vectors and scalars themselves are also tensors. A tensor can be represented as a multi-dimensional array of...

) or whether the quantity is conserved.

Base quantity	Symbol	Description	SI unit	Symbol for dimension	Comments
Length Length In geometric measurements, length most commonly refers to the longest dimension of an object.In certain contexts, the term "length" is reserved for a certain dimension of an object along which the length is measured. For example it is possible to cut a length of a wire which is shorter than wire...	l	The one dimensional extent of an object.	metre Metre The metre , symbol m, is the base unit of length in the International System of Units . Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole , its definition has been periodically refined to reflect growing knowledge of metrology...  (m)	L
Mass Mass Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...	m	The amount of matter in an object.	kilogram Kilogram The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...  (kg)	M	extensive
Time Time Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....	t	The duration of an event.	second Second The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....  (s)	T
Electric current	I	Rate of flow of electrical charge.	ampere Ampere The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...  (A)	I
Temperature Temperature Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...	T	Average energy Energy In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...  per degree of freedom Degrees of freedom (physics and chemistry) A degree of freedom is an independent physical parameter, often called a dimension, in the formal description of the state of a physical system...  of a system.	kelvin Kelvin The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...  (K)	Θ	intensive
Amount of substance Amount of substance Amount of substance is a standards-defined quantity that measures the size of an ensemble of elementary entities, such as atoms, molecules, electrons, and other particles. It is sometimes referred to as chemical amount. The International System of Units defines the amount of substance to be...	n	Number of particles compared to the number of atoms in 0.012 kg of 12C Carbon-12 Carbon-12 is the more abundant of the two stable isotopes of the element carbon, accounting for 98.89% of carbon; it contains 6 protons, 6 neutrons, and 6 electrons.... .	mole Mole (unit) The mole is a unit of measurement used in chemistry to express amounts of a chemical substance, defined as an amount of a substance that contains as many elementary entities as there are atoms in 12 grams of pure carbon-12 , the isotope of carbon with atomic weight 12. This corresponds to a value...  (mol)	N	extensive
Luminous intensity Luminous intensity In photometry, luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye...	L	Amount of energy emitted by a light source in a particular direction.	candela Candela The candela is the SI base unit of luminous intensity; that is, power emitted by a light source in a particular direction, weighted by the luminosity function . A common candle emits light with a luminous intensity of roughly one candela...  (cd)	J

Derived quantity	Symbol	Description	SI units	Dimension	Comments
Plane angle Angle In geometry, an angle is the figure formed by two rays sharing a common endpoint, called the vertex of the angle.Angles are usually presumed to be in a Euclidean plane with the circle taken for standard with regard to direction. In fact, an angle is frequently viewed as a measure of an circular arc...	θ	Measure of a change in direction or orientation.	radian Radian Radian is the ratio between the length of an arc and its radius. The radian is the standard unit of angular measure, used in many areas of mathematics. The unit was formerly a SI supplementary unit, but this category was abolished in 1995 and the radian is now considered a SI derived unit...  (rad)	1
Solid angle Solid angle The solid angle, Ω, is the two-dimensional angle in three-dimensional space that an object subtends at a point. It is a measure of how large that object appears to an observer looking from that point...	Ω	Measure of the size of an object as projected on a sphere.	steradian Steradian The steradian is the SI unit of solid angle. It is used to describe two-dimensional angular spans in three-dimensional space, analogous to the way in which the radian describes angles in a plane...  (sr)	1
Absorbed dose rate		Absorbed dose Absorbed dose Absorbed dose is a measure of the energy deposited in a medium by ionizing radiation per unit mass...  received per unit of time.	Gy s−1	L2 T−3
Acceleration Acceleration In physics, acceleration is the rate of change of velocity with time. In one dimension, acceleration is the rate at which something speeds up or slows down. However, since velocity is a vector, acceleration describes the rate of change of both the magnitude and the direction of velocity. ...	a	Rate of change of the speed or velocity of an object.	m s−2	L T−2	vector
Angular acceleration Angular acceleration Angular acceleration is the rate of change of angular velocity over time. In SI units, it is measured in radians per second squared , and is usually denoted by the Greek letter alpha .- Mathematical definition :...	α	Rate of change in angular speed or velocity.	rad s−2	T−2
Angular speed (or angular velocity Angular velocity In physics, the angular velocity is a vector quantity which specifies the angular speed of an object and the axis about which the object is rotating. The SI unit of angular velocity is radians per second, although it may be measured in other units such as degrees per second, revolutions per... )	ω or ω	The angle incremented in a plane by a segment connecting an object and a reference point.	rad s−1	T−1	scalar or pseudovector
Angular momentum Angular momentum In physics, angular momentum, moment of momentum, or rotational momentum is a conserved vector quantity that can be used to describe the overall state of a physical system...	L	Measure of the extent and direction and object rotates about a reference point.	kg m2 s−1	M L2 T−1	conserved quantity, pseudovector
Area Area Area is a quantity that expresses the extent of a two-dimensional surface or shape in the plane. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat...	A	The two dimensional extent of an object.	m2	L2
Area density	ρA	The amount of mass per unit area of a two dimensional object.	kg m−2	M L−2
Capacitance Capacitance In electromagnetism and electronics, capacitance is the ability of a capacitor to store energy in an electric field. Capacitance is also a measure of the amount of electric potential energy stored for a given electric potential. A common form of energy storage device is a parallel-plate capacitor...	C	Measure for the amount of stored charge for a given potential.	farad Farad The farad is the SI unit of capacitance. The unit is named after the English physicist Michael Faraday.- Definition :A farad is the charge in coulombs which a capacitor will accept for the potential across it to change 1 volt. A coulomb is 1 ampere second...  (F = A2 s4 kg−1 m−2)	I2 T4 M−1 L−2
Catalytic activity		Change in reaction rate Reaction rate The reaction rate or speed of reaction for a reactant or product in a particular reaction is intuitively defined as how fast or slow a reaction takes place...  due to presence of a catalyst.	katal Katal The katal is the SI unit of catalytic activity. It is a derived SI unit for expressing quantity values of catalytic activity of enzymes and other catalysts. Its use is recommended by the General Conference on Weights and Measures and other international organizations. It replaces the non-SI enzyme...  (kat = mol s−1)	N T−1
Catalytic activity concentration		Change in reaction rate Reaction rate The reaction rate or speed of reaction for a reactant or product in a particular reaction is intuitively defined as how fast or slow a reaction takes place...  due to presence of a catalyst per unit volume of the system.	kat m−3	N L−3 T−1
Chemical potential Chemical potential Chemical potential, symbolized by μ, is a measure first described by the American engineer, chemist and mathematical physicist Josiah Willard Gibbs. It is the potential that a substance has to produce in order to alter a system...	μ	The amount of energy needed to add a particle to a system.	J mol−1	M L2 T−2 N−1	intensive
Molar concentration	C	Amount of substance per unit volume.	mol m−3	N L−3	intensive
Current density Current density Current density is a measure of the density of flow of a conserved charge. Usually the charge is the electric charge, in which case the associated current density is the electric current per unit area of cross section, but the term current density can also be applied to other conserved...	J	Amount of electric current flowing through a surface.	A m−2	I L−2
Dose equivalent	H	Measure for the received amount of radiation adjusted for the effect of different types of radiant on biological tissue.	sievert Sievert The sievert is the International System of Units SI derived unit of dose equivalent radiation. It attempts to quantitatively evaluate the biological effects of ionizing radiation as opposed to just the absorbed dose of radiation energy, which is measured in gray...  (Sv = m2 s−2)	L2 T−2
Dynamic Viscosity	η	Measure for the resistance of an incompressible fluid to stress.	Pa s	M L−1 T−1
Electric Charge Electric charge Electric charge is a physical property of matter that causes it to experience a force when near other electrically charged matter. Electric charge comes in two types, called positive and negative. Two positively charged substances, or objects, experience a mutual repulsive force, as do two...	Q	Amount of electric charge.	coulomb (C = A s)	I T	extensive, conserved quantity
Electric charge density	ρQ	Amount of electric charge per unit volume.	C m−3	I T L−3	intensive
Electric displacement	D	Strength of the electric displacement.	C m−2	I T L−2	vector field
Electric field strength	E	Strength of the electric field.	V m−1	M I−1 L2 T−3	vector field
Electrical conductance	G	Meausure for how easily current flows through a material.	siemens Siemens (unit) The siemens is the SI derived unit of electric conductance and electric admittance. Conductance and admittance are the reciprocals of resistance and impedance respectively, hence one siemens is equal to the reciprocal of one ohm, and is sometimes referred to as the mho. In English, the term...  (S = A2 s3 kg−1 m−2)	L−2 M−1 T3 I2	scalar
Electric potential Electric potential In classical electromagnetism, the electric potential at a point within a defined space is equal to the electric potential energy at that location divided by the charge there...	V	The amount of work required to bring a unit charge into an electric field from infinity.	volt Volt The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...  (V = kg m2 A−1 s−3)	L2 M T−3 I−1	scalar
Electrical resistance Electrical resistance The electrical resistance of an electrical element is the opposition to the passage of an electric current through that element; the inverse quantity is electrical conductance, the ease at which an electric current passes. Electrical resistance shares some conceptual parallels with the mechanical...	R	The degree to which an object opposes the passage of an electric current.	ohm (Ω = kg m2 A−2 s−3)	L2 M T−3 I−2	scalar
Energy Energy In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...	E	The capacity of a body or system to do work.	joule Joule The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...  (J = kg m2 s−2)	M L2 T−2	extensive, scalar, conserved quantity
Energy density Energy density Energy density is a term used for the amount of energy stored in a given system or region of space per unit volume. Often only the useful or extractable energy is quantified, which is to say that chemically inaccessible energy such as rest mass energy is ignored...	ρE	Amount of energy per unit volume.	J m−3	M L−1 T−2	intensive
Entropy Entropy Entropy is a thermodynamic property that can be used to determine the energy available for useful work in a thermodynamic process, such as in energy conversion devices, engines, or machines. Such devices can only be driven by convertible energy, and have a theoretical maximum efficiency when...	S	Measure for the amount of available states for a system.	J K−1	M L2 T−2 Θ−1	extensive, scalar
Force Force In physics, a force is any influence that causes an object to undergo a change in speed, a change in direction, or a change in shape. In other words, a force is that which can cause an object with mass to change its velocity , i.e., to accelerate, or which can cause a flexible object to deform...	F	The cause of acceleration, acting on an object.	newton (N = kg m s−2)	M L T−2	vector
Impulse Impulse In classical mechanics, an impulse is defined as the integral of a force with respect to time. When a force is applied to a rigid body it changes the momentum of that body...	p	The cause of a change in momentum, acting on an object.	kg m s−1	M L T−1	vector
Frequency Frequency Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...	f	The number of times something happens in a period of time.	hertz Hertz The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....  (Hz =s−1)	T−1
Half-life Half-life Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...	t1/2	The time needed for a quantity to decay to half its original value.	s	T
Heat Heat In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...	Q	Amount of energy transferred between systems due to temperature difference.	J	M L2 T−2
Heat capacity Heat capacity Heat capacity , or thermal capacity, is the measurable physical quantity that characterizes the amount of heat required to change a substance's temperature by a given amount...	Cp	Amount of energy needed to raise the temperature of a system by one degree.	J K−1	M L2 T−2 Θ−1	extensive
Heat flux density Heat flux Heat flux or thermal flux is the rate of heat energy transfer through a given surface. The SI derived unit of heat rate is joule per second, or watt. Heat flux is the heat rate per unit area. In SI units, heat flux is measured in W/m2]. Heat rate is a scalar quantity, while heat flux is a vectorial...	Q	Amount of heat flowing through a surface per unit area.	W m−2	M T−3
Illuminance Illuminance In photometry, illuminance is the total luminous flux incident on a surface, per unit area. It is a measure of the intensity of the incident light, wavelength-weighted by the luminosity function to correlate with human brightness perception. Similarly, luminous emittance is the luminous flux per...	Ev	Total luminous flux incident to a surface per unit area.	lux Lux The lux is the SI unit of illuminance and luminous emittance, measuring luminous flux per unit area. It is used in photometry as a measure of the intensity, as perceived by the human eye, of light that hits or passes through a surface...  (lx = cd sr m−2)	J L−2
Impedance Electrical impedance Electrical impedance, or simply impedance, is the measure of the opposition that an electrical circuit presents to the passage of a current when a voltage is applied. In quantitative terms, it is the complex ratio of the voltage to the current in an alternating current circuit...	Z	Measure for the resistance of an electrical circuit against an alternating current.	ohm (Ω = kg m2 A−2 s−3)	L2 M T−3 I−2	complex scalar
Index of refraction	n	The factor by which the speed of light Speed of light The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...  is reduce in a medium.		1	intensive
Inductance Inductance In electromagnetism and electronics, inductance is the ability of an inductor to store energy in a magnetic field. Inductors generate an opposing voltage proportional to the rate of change in current in a circuit...	L	Measure for the amount of magnetic flux generated for a certain current run through a circuit.	henry (H = kg m2 A−2 s−2)	M L2 T−2 I−2
Irradiance Irradiance Irradiance is the power of electromagnetic radiation per unit area incident on a surface. Radiant emittance or radiant exitance is the power per unit area radiated by a surface. The SI units for all of these quantities are watts per square meter , while the cgs units are ergs per square centimeter...	E	Power of electromagnetic radiation flowing through a surface per unit area.	W m−2	M T−2
Linear density Linear density Linear density, linear mass density or linear mass is a measure of mass per unit of length, and it is a characteristic of strings or other one-dimensional objects. The SI unit of linear density is the kilogram per metre...	ρl	Amount of mass per unit length of a one dimensional object.		M L−1
Luminous flux Luminous flux In photometry, luminous flux or luminous power is the measure of the perceived power of light. It differs from radiant flux, the measure of the total power of light emitted, in that luminous flux is adjusted to reflect the varying sensitivity of the human eye to different wavelengths of...  (or luminous power)	F	Perceived power of a light source.	lumen Lumen (unit) The lumen is the SI derived unit of luminous flux, a measure of the total "amount" of visible light emitted by a source. Luminous flux differs from power in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux...  (lm = cd sr)	J
Magnetic field strength	H	Strength of a magnetic field in a material.	A m−1	I L−1	vector field
Magnetic flux Magnetic flux Magnetic flux , is a measure of the amount of magnetic B field passing through a given surface . The SI unit of magnetic flux is the weber...	Φ	Measure of quantity of magnetism Magnetism Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well... , taking account of the strength and the extent of a magnetic field Magnetic field A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;... .	weber Weber (unit) In physics, the weber is the SI unit of magnetic flux. A flux density of one Wb/m2 is one tesla.The weber is named for the German physicist Wilhelm Eduard Weber .- Definition :...  (Wb = kg m2 A−1 s−2)	M L2 T−2 I−1	scalar
Magnetic flux density	B	Measure for the strength of the magnetic field.	tesla Tesla (unit) The tesla is the SI derived unit of magnetic field B . One tesla is equal to one weber per square meter, and it was defined in 1960 in honour of the inventor, physicist, and electrical engineer Nikola Tesla...  (T = kg A−1 s−2)	M T−2 I−1	pseudovector field
Magnetization Magnetization In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material...	M	Amount of magnetic moment per unit volume.	A m−1	I L−1	vector field
Mass fraction Mass fraction In aerospace engineering, the propellant mass fraction is a measure of a vehicle's performance, determined as the portion of the vehicle's mass which does not reach the destination...	x	Mass of a substance as a fraction of the total mass.	kg/kg	1	intensive
(Mass) Density Density The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...  (volume density)	ρ	The amount of mass per unit volume of a three dimensional object.	kg m−3	M L−3	intensive
Mean lifetime	τ	Average time needed for a particle to decay.	s	T	intensive
Molar energy		Amount of energy present is a system per unit amount of substance.	J mol−1	M L2 T−2 N−1	intensive
Molar entropy		Amount of entropy present in a system per unit amount of substance.	J K−1 mol−1	M L2 T−2 Θ−1 N−1	intensive
Molar heat capacity	c	Heat capacity of a material per unit amount of substance.	J K−1 mol−1	M L2 T−2 N−1	intensive
Moment of inertia Moment of inertia In classical mechanics, moment of inertia, also called mass moment of inertia, rotational inertia, polar moment of inertia of mass, or the angular mass, is a measure of an object's resistance to changes to its rotation. It is the inertia of a rotating body with respect to its rotation...	I	Inertia of an object with respect to angular acceleration.	kg m2	M L2	scalar
Momentum Momentum In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object...	p	Product of an object's mass and velocity.	N s	M L T−1	vector, extensive
Permeability Permeability (electromagnetism) In electromagnetism, permeability is the measure of the ability of a material to support the formation of a magnetic field within itself. In other words, it is the degree of magnetization that a material obtains in response to an applied magnetic field. Magnetic permeability is typically...	μ	Measure for how the magnetization of material is affected by the application of an external magnetic field.	H m−1	M L−1 I−2	intensive
Permittivity Permittivity In electromagnetism, absolute permittivity is the measure of the resistance that is encountered when forming an electric field in a medium. In other words, permittivity is a measure of how an electric field affects, and is affected by, a dielectric medium. The permittivity of a medium describes how...	ε	Measure for how the polarization of a material is affected by the application of an external electric field.	F m−1	I2 M−1 L−2 T4	intensive
Power Power (physics) In physics, power is the rate at which energy is transferred, used, or transformed. For example, the rate at which a light bulb transforms electrical energy into heat and light is measured in watts—the more wattage, the more power, or equivalently the more electrical energy is used per unit...	P	The rate of change in energy over time.	watt Watt The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...  (W)	M L2 T−3	extensive
Pressure Pressure Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...	p	Amount of force per unit area.	pascal Pascal (unit) The pascal is the SI derived unit of pressure, internal pressure, stress, Young's modulus and tensile strength, named after the French mathematician, physicist, inventor, writer, and philosopher Blaise Pascal. It is a measure of force per unit area, defined as one newton per square metre...  (Pa = kg m−1 s−2)	M L−1 T−2	intensive
(Radioactive) Activity	A	Number of particles decaying per unit time.	becquerel Becquerel The becquerel is the SI-derived unit of radioactivity. One Bq is defined as the activity of a quantity of radioactive material in which one nucleus decays per second. The Bq unit is therefore equivalent to an inverse second, s−1...  (Bq = s−1)	T−1	extensive
(Radioactive) Dose Absorbed dose Absorbed dose is a measure of the energy deposited in a medium by ionizing radiation per unit mass...	D	Amount of energy absorbed by biological tissue from ionizing radiation per unit mass.	gray (unit) Gray (unit) The gray is the SI unit of absorbed radiation dose of ionizing radiation , and is defined as the absorption of one joule of ionizing radiation by one kilogram of matter ....  (Gy = m2 s−2)	L2 T−2
Radiance Radiance Radiance and spectral radiance are radiometric measures that describe the amount of radiation such as light or radiant heat that passes through or is emitted from a particular area, and falls within a given solid angle in a specified direction. They are used to characterize both emission from...	L	Power of emitted electromagnetic radiation per solid angle and per projected source area.	W m−2 sr−1	M T−3
Radiant intensity Radiant intensity In radiometry, radiant intensity is a measure of the intensity of electromagnetic radiation. It is defined as power per unit solid angle. The SI unit of radiant intensity is watts per steradian . Radiant intensity is distinct from irradiance and radiant exitance, which are often called intensity...	I	Power of emitted electromagnetic radiation per solid angle.	W sr−1	M L2 T−3	scalar
Reaction rate Reaction rate The reaction rate or speed of reaction for a reactant or product in a particular reaction is intuitively defined as how fast or slow a reaction takes place...	r	Measure for speed of a chemical reaction.	mol m−3 s−1	N L−3 T−1	intensive
Speed Speed In kinematics, the speed of an object is the magnitude of its velocity ; it is thus a scalar quantity. The average speed of an object in an interval of time is the distance traveled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as...	v	Rate of change of the position of an object.	m s−1	L T−1	scalar
Specific energy Specific energy Specific energy is defined as the energy per unit mass. Common metric units are J/kg. It is an intensive property. Contrast this with energy, which is an extensive property. There are two main types of specific energy: potential energy and specific kinetic energy. Others are the gray and sievert,...		Amount of energy present per unit mass.	J kg−1	L2 T−2	intensive
Specific heat capacity	c	Heat capacity per unit mass.	J kg−1 K−1	L2 T−2 Θ−1	intensive
Specific volume Specific volume In thermodynamics, the specific volume of a substance is the ratio of the substance's volume to its mass. It is the reciprocal of density:In thermodynamics, the specific volume of a substance is the ratio of the substance's volume to its mass...	v	The volume occupied by a unit mass of material (reciprocal of density).	m3 kg−1	L3 M−1	intensive
Spin Spin (physics) In quantum mechanics and particle physics, spin is a fundamental characteristic property of elementary particles, composite particles , and atomic nuclei.It is worth noting that the intrinsic property of subatomic particles called spin and discussed in this article, is related in some small ways,...	S	Intrinsic property of particles, roughly to be interpreted as the intrinsic angular momentum Angular momentum In physics, angular momentum, moment of momentum, or rotational momentum is a conserved vector quantity that can be used to describe the overall state of a physical system...  of the particle.	kg m2 s−1	M L2 T−1
Stress Stress (physics) In continuum mechanics, stress is a measure of the internal forces acting within a deformable body. Quantitatively, it is a measure of the average force per unit area of a surface within the body on which internal forces act. These internal forces are a reaction to external forces applied on the body...	σ	Amount of force exerted per surface area.	Pa	M L−1 T−2	2-tensor. (or scalar)
Surface tension Surface tension Surface tension is a property of the surface of a liquid that allows it to resist an external force. It is revealed, for example, in floating of some objects on the surface of water, even though they are denser than water, and in the ability of some insects to run on the water surface...	γ	Amount of work needed to change the surface of a liquid by a unit surface area.	N m−1 or J m−2	M T−2
Thermal conductivity Thermal conductivity In physics, thermal conductivity, k, is the property of a material's ability to conduct heat. It appears primarily in Fourier's Law for heat conduction....	k	Measure for the ease with which a material conducts heat.	W m−1 K−1	M L−1 T−3 Θ−1	intensive
Torque Torque Torque, moment or moment of force , is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist....  (moment Moment (physics) In physics, the term moment can refer to many different concepts:*Moment of force is the tendency of a force to twist or rotate an object; see the article torque for details. This is an important, basic concept in engineering and physics. A moment is valued mathematically as the product of the...  of force)	T	Product of a force and the perpendicular distance of the force from the point about which it is exerted.	N m	M L2 T−2	pseudovector
Velocity Velocity In physics, velocity is speed in a given direction. Speed describes only how fast an object is moving, whereas velocity gives both the speed and direction of the object's motion. To have a constant velocity, an object must have a constant speed and motion in a constant direction. Constant ...	v	Speed of an object in a chosen direction.	m s−1	L T−1	vector
Volume Volume Volume is the quantity of three-dimensional space enclosed by some closed boundary, for example, the space that a substance or shape occupies or contains....	V	The three dimensional extent of an object.	m3	L3	extensive
Wavelength Wavelength In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...	λ	Distance between repeating units of a propagating wave.	m	L
Wavenumber Wavenumber In the physical sciences, the wavenumber is a property of a wave, its spatial frequency, that is proportional to the reciprocal of the wavelength. It is also the magnitude of the wave vector...	k	Reciprocal of the wavelength.	m−1	L−1
Weight Weight In science and engineering, the weight of an object is the force on the object due to gravity. Its magnitude , often denoted by an italic letter W, is the product of the mass m of the object and the magnitude of the local gravitational acceleration g; thus:...	w	Amount of gravitation force exerted on an object.	newton (N = kg m s−2)	M L T−2
Work Mechanical work In physics, work is a scalar quantity that can be described as the product of a force times the distance through which it acts, and it is called the work of the force. Only the component of a force in the direction of the movement of its point of application does work...	W	Energy dissipated by a force moving over a distance, scalar product of the force and the movement vector.	joule Joule The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second... (J = kg m2 s−2)	M L2 T−2	scalar