View source for Density

{{Short description|Mass per unit volume}}
{{About|mass density}}
{{pp-vandalism|small=yes}}
{{pp-move}}
{{Use mdy dates|date=October 2015}}
{{Infobox physical quantity
| bgcolour = 
| name = Density
| image = Density column.JPG
| image_size = 100px
| caption = A [[test tube]] holding four [[Miscibility|non-miscible]] colored liquids with different densities
| unit = kg/m<sup>3</sup>
| symbols = ''[[Rho|ρ]]'', ''D''
| dimension = wikidata
| extensive = No
| intensive = Yes
| conserved = No
| derivations = <math> \rho = \frac{m}{V}</math>
}}
'''Density''' ('''volumetric mass density''' or '''specific mass''') is a substance's [[mass]] per unit of [[volume]]. The symbol most often used for density is ''ρ'' (the lower case [[Greek language|Greek]] letter [[rho]]), although the Latin letter ''D'' can also be used. Mathematically, density is defined as mass divided by volume:<ref>{{cite web | url =http://www.grc.nasa.gov/WWW/BGH/fluden.html | title =Gas Density  | publisher = [[National Aeronautic and Space Administration]] |website=[[Glenn Research Center]] | url-status =dead | archive-url =https://web.archive.org/web/20130414132531/http://www.grc.nasa.gov/WWW/BGH/fluden.html | archive-date =April 14, 2013 | df =mdy-all | access-date =April 9, 2013 }}</ref> 
<math display="block"> \rho = \frac{m}{V},</math>
where ''ρ'' is the density, ''m'' is the mass, and ''V'' is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its [[weight]] per unit [[volume]],<ref>{{cite web|url=http://oilgasglossary.com/density.html |title=Density definition  |publisher= Oil Gas Glossary |access-date=September 14, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100805010226/http://oilgasglossary.com/density.html |archive-date=August 5, 2010 }}</ref> although this is scientifically inaccurate{{snd}} this quantity is more specifically called [[specific weight]].

For a pure substance the density has the same numerical value as its [[mass concentration (chemistry)|mass concentration]].
Different materials usually have different densities, and density may be relevant to [[buoyancy]], purity and [[packaging]]. [[Osmium]] is the densest known element at [[standard conditions for temperature and pressure]].

To simplify comparisons of density across different systems of units, it is sometimes replaced by the [[dimensionless]] quantity "[[relative density]]" or "[[specific gravity]]", i.e. the ratio of the density of the material to that of a standard material, usually water. Thus a relative density less than one relative to water means that the substance floats in water.

The density of a material varies with temperature and pressure. This variation is typically small for solids and liquids but much greater for gases. Increasing the pressure on an object decreases the volume of the object and thus increases its density. Increasing the temperature of a substance (with a few exceptions) decreases its density by increasing its volume. In most materials, heating the bottom of a fluid results in [[convection]] of the heat from the bottom to the top, due to the decrease in the density of the heated fluid, which causes it to rise relative to denser unheated material.

The reciprocal of the density of a substance is occasionally called its [[specific volume]], a term sometimes used in [[thermodynamics]]. Density is an [[intensive property]] in that increasing the amount of a substance does not increase its density; rather it increases its mass.

Other conceptually comparable quantities or ratios include [[specific density]], [[relative density|relative density (specific gravity)]], and [[specific weight]].

== History ==

=== Density, floating, and sinking ===
The understanding that different materials have different densities, and of a relationship between density, floating, and sinking must date to prehistoric times. Much later it was put in writing. [[Aristotle]], for example, wrote:<ref>{{Cite book |last=Aristotle. |url=https://archive.org/details/aristotle0000hdpl/page/n7/mode/2up |title=Meteorologica |publisher=Harvard University Press |year=1952 |pages=2.3, 359a |language=Ancient Greek, English |translator-last=Lee |translator-first=H. D. P. |orig-date=c. 340 BC}}</ref>
{{Blockquote|text=There is so great a difference in density between salt and fresh water that vessels laden with cargoes of the same weight almost sink in rivers, but ride quite easily at sea and are quite seaworthy. And an ignorance of this has sometimes cost people dear who load their ships in rivers. The following is a proof that the density of a fluid is greater when a substance is mixed with it. If you make water very salt by mixing salt in with it, eggs will float on it. ... If there were any truth in the stories they tell about the lake in Palestine it would further bear out what I say. For they say if you bind a man or beast and throw him into it he floats and does not sink beneath the surface.|author=Aristotle|title=[[Meteorologica]]|source=Book II, Chapter III}}

=== Volume vs. density; volume of an irregular shape ===
{{Main|Eureka (word)#Archimedes}}
{{See also|Archimedes#Archimedes and the gold crown}}
In a well-known but probably [[apocrypha]]l tale, [[Archimedes]] was given the task of determining whether [[Hiero II of Syracuse|King Hiero]]'s [[goldsmith]] was embezzling [[gold]] during the manufacture of a golden [[wreath]] dedicated to the gods and replacing it with another, cheaper [[alloy]].<ref>[http://www-personal.umich.edu/~lpt/archimedes.htm Archimedes, A Gold Thief and Buoyancy] {{webarchive|url=https://web.archive.org/web/20070827113533/http://www-personal.umich.edu/~lpt/archimedes.htm |date=August 27, 2007 }} – by Larry "Harris" Taylor, Ph.D.</ref> Archimedes knew that the irregularly shaped wreath could be crushed into a cube whose volume could be calculated easily and compared with the mass; but the king did not approve of this. Baffled, Archimedes is said to have taken an immersion bath and observed from the rise of the water upon entering that he could calculate the volume of the gold wreath through the [[Displacement (fluid)|displacement]] of the water. Upon this discovery, he leapt from his bath and ran naked through the streets shouting, "Eureka! Eureka!" ({{langx|grc|Εύρηκα!||I have found it}}). As a result, the term ''[[Eureka (word)|eureka]]'' entered common parlance and is used today to indicate a moment of enlightenment.

The story first appeared in written form in [[Vitruvius]]' ''[[De architectura|books of architecture]]'', two centuries after it supposedly took place.<ref>[http://webarchive.loc.gov/all/20210420024146/https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Vitruvius/9%2A.html Vitruvius on Architecture, Book IX], paragraphs 9–12, translated into English and [https://penelope.uchicago.edu/Thayer/L/Roman/Texts/Vitruvius/9*.html in the original Latin].</ref> Some scholars have doubted the accuracy of this tale, saying among other things that the method would have required precise measurements that would have been difficult to make at the time.<ref>{{cite journal|doi=10.1126/science.305.5688.1219e|title=EXHIBIT: The First Eureka Moment| year=2004| journal=Science|volume=305|issue=5688|pages=1219e |doi-access=free}}</ref><ref>{{cite news |first=David |last=Biello |title=Fact or Fiction?: Archimedes Coined the Term "Eureka!" in the Bath | work = Scientific American | date = 2006-12-08 |url=https://www.scientificamerican.com/article/fact-or-fiction-archimede }}</ref>

Nevertheless, in 1586, [[Galileo Galilei]], in one of his first experiments, made a possible reconstruction of how the experiment could have been performed with ancient Greek resources<ref>La Bilancetta, Complete text of Galileo's treatise in the original Italian together with a modern English translation [https://math.nyu.edu/~crorres/Archimedes/Crown/bilancetta.html]</ref>

==Units{{anchor|Unit}}==
From the equation for density ({{math|1=''ρ'' = ''m''/''V''}}), mass density has any unit that is ''mass divided by volume''. As there are many units of mass and volume covering many different magnitudes there are a large number of units for mass density in use. The [[SI]] unit of [[kilogram per cubic metre]] (kg/m<sup>3</sup>) and the [[cgs]] unit of [[gram]] per [[cubic centimetre]] (g/cm<sup>3</sup>) are probably the most commonly used units for density. One g/cm<sup>3</sup> is equal to 1000&nbsp;kg/m<sup>3</sup>.  One cubic centimetre (abbreviation cc) is equal to one millilitre. In industry, other larger or smaller units of mass and or volume are often more practical and [[US customary units]] may be used. See below for a list of some of the most common units of density.

The litre and tonne are not part of the SI, but are acceptable for use with it, leading to the following units:
* [[kilogram]] per [[litre]] (kg/L)
* [[gram]] per [[millilitre]] (g/mL)
* [[tonne]] per cubic metre (t/m<sup>3</sup>)

Densities using the following metric units all have exactly the same numerical value, one thousandth of the value in (kg/m<sup>3</sup>). Liquid [[water]] has a density of about 1&nbsp;kg/dm<sup>3</sup>, making any of these SI units numerically convenient to use as most [[solid]]s and [[liquid]]s have densities between 0.1 and 20&nbsp;kg/dm<sup>3</sup>.
* kilogram per cubic decimetre (kg/dm<sup>3</sup>)
* gram per cubic centimetre (g/cm<sup>3</sup>)
** 1 g/cm<sup>3</sup> = 1000&nbsp;kg/m<sup>3</sup>
* megagram (metric ton) per cubic metre (Mg/m<sup>3</sup>)

In [[US customary units]] density can be stated in:
* [[Avoirdupois ounce]] per [[cubic inch]] (1 g/cm<sup>3</sup> ≈ 0.578036672 oz/cu&nbsp;in)
* [[Avoirdupois ounce]] per [[fluid ounce]] (1 g/cm<sup>3</sup> ≈ 1.04317556 oz/US fl oz = 1.04317556&nbsp;lb/US fl pint)
* [[Pound (mass)|Avoirdupois pound]] per cubic inch (1 g/cm<sup>3</sup> ≈ 0.036127292&nbsp;lb/cu&nbsp;in)
* pound per [[cubic foot]] (1 g/cm<sup>3</sup> ≈ 62.427961&nbsp;lb/cu&nbsp;ft)
* pound per [[cubic yard]] (1 g/cm<sup>3</sup> ≈ 1685.5549&nbsp;lb/cu&nbsp;yd)
* pound per [[US liquid gallon]] (1 g/cm<sup>3</sup> ≈ 8.34540445&nbsp;lb/US gal)
* pound per US [[bushel]] (1 g/cm<sup>3</sup> ≈ 77.6888513&nbsp;lb/bu)
* [[slug (unit)|slug]] per cubic foot

[[Imperial units]] differing from the above (as the Imperial gallon and bushel differ from the US units) in practice are rarely used, though found in older documents. The Imperial gallon was based on the concept that an [[Imperial fluid ounce]] of water would have a mass of one Avoirdupois ounce, and indeed 1&nbsp;g/cm<sup>3</sup> ≈ 1.00224129 ounces per Imperial fluid ounce = 10.0224129 pounds per Imperial gallon. The density of [[precious metal]]s could conceivably be based on [[Troy weight|Troy]] ounces and pounds, a possible cause of confusion.

Knowing the volume of the [[unit cell]] of a crystalline material and its formula weight (in [[Dalton (unit)|daltons]]), the density can be calculated. One dalton per cubic [[ångström]] is equal to a density of 1.660&nbsp;539&nbsp;066&nbsp;60&nbsp;g/cm<sup>3</sup>.

== Measurement ==
A number of techniques as well as standards exist for the measurement of density of materials. Such techniques include the use of a hydrometer (a buoyancy method for liquids), Hydrostatic balance (a buoyancy method for liquids and solids), immersed body method (a buoyancy method for liquids), pycnometer (liquids and solids), air comparison pycnometer (solids), oscillating densitometer (liquids), as well as pour and tap (solids).<ref>{{cite journal |title=Test No. 109: Density of Liquids and Solids  |journal=OECD Guidelines for the Testing of Chemicals, Section 1 |volume= |issue= |pages=6 |date=2 October 2012 |doi=10.1787/9789264123298-en |isbn=9789264123298 |url= |issn=2074-5753 }}</ref> However, each individual method or technique measures different types of density (e.g. bulk density, skeletal density, etc.), and therefore it is necessary to have an understanding of the type of density  being measured as well as the type of material in question.

===Homogeneous materials===
The density at all points of a [[Homogeneous (chemistry)|homogeneous]] object equals its total [[mass]] divided by its total volume. The mass is normally measured with a [[weighing scale|scale or balance]]; the volume may be measured directly (from the geometry of the object) or by the displacement of a fluid. To determine the density of a liquid or a gas, a [[hydrometer]], a [[dasymeter]] or a [[Coriolis flow meter]] may be used, respectively. Similarly, [[hydrostatic weighing]] uses the displacement of water due to a submerged object to determine the density of the object.

===Heterogeneous materials===
If the body is not homogeneous, then its density varies between different regions of the object. In that case the density around any given location is determined by calculating the density of a small volume around that location. In the limit of an infinitesimal volume the density of an inhomogeneous object at a point becomes: <math>\rho(\vec{r}) = dm / dV</math>, where <math>dV</math> is an elementary volume at position <math>\vec r</math>. The mass of the body then can be expressed as
<math display="block"> m = \int_V \rho(\vec{r})\,dV. </math>

=== Non-compact materials ===
{{further|Bulk density|Particle mass density}}

In practice, bulk materials such as sugar, sand, or snow contain voids. Many materials exist in nature as flakes, pellets, or granules.

Voids are regions which contain something other than the considered material.  Commonly the void is air, but it could also be vacuum,  liquid, solid, or a different gas or gaseous mixture.

The ''[[bulk volume]]'' of a material —inclusive of the [[void space fraction]]— is often obtained by a simple measurement (e.g. with a calibrated measuring cup) or geometrically from known dimensions.

Mass divided by bulk volume determines ''[[bulk density]]''.  This is not the same thing as the material volumetric mass density.
To determine the material volumetric mass density, one must first discount the volume of the void fraction. Sometimes this can be determined by geometrical reasoning.  For the [[close-packing of equal spheres]] the non-void fraction can be at most about 74%.  It can also be determined empirically.  Some bulk materials, however, such as sand, have a ''variable'' void fraction which depends on how the material is agitated or poured. It might be loose or compact, with more or less air space depending on handling.

In practice, the void fraction is not necessarily air, or even gaseous.  In the case of sand, it could be water, which can be advantageous for measurement as the void fraction for sand saturated in water—once any air bubbles are thoroughly driven out—is potentially more consistent than dry sand measured with an air void.

In the case of non-compact materials, one must also take care in determining the mass of the material sample. If the material is under pressure (commonly ambient air pressure at the earth's surface) the determination of mass from a measured sample weight might need to account for buoyancy effects due to the density of the void constituent, depending on how the measurement was conducted. In the case of dry sand, sand is so much denser than air that the buoyancy effect is commonly neglected (less than one part in one thousand).

Mass change upon displacing one void material with another while maintaining constant volume can be used to estimate the void fraction, if the difference in density of the two voids materials is reliably known.

== Changes of density ==
{{Main article|Compressibility|Thermal expansivity}}

In general, density can be changed by changing either the [[pressure]] or the [[temperature]]. Increasing the pressure always increases the density of a material. Increasing the temperature generally decreases the density, but there are notable exceptions to this generalization. For example, the density of [[water]] increases between its melting point at 0&nbsp;°C and 4&nbsp;°C; similar behavior is observed in [[silicon]] at low temperatures.

The effect of pressure and temperature on the densities of liquids and solids is small. The [[compressibility]] for a typical liquid or solid is 10<sup>−6</sup>&nbsp;[[bar (unit)|bar]]<sup>−1</sup> (1&nbsp;bar = 0.1&nbsp;MPa) and a typical [[thermal expansivity]] is 10<sup>−5</sup>&nbsp;[[Kelvin|K]]<sup>−1</sup>. This roughly translates into needing around ten thousand times atmospheric pressure to reduce the volume of a substance by one percent. (Although the pressures needed may be around a thousand times smaller for sandy soil and some clays.) A one percent expansion of volume typically requires a temperature increase on the order of thousands of degrees [[Celsius]].

In contrast, the density of gases is strongly affected by pressure. The density of an [[ideal gas]] is
<math display="block">\rho = \frac {MP}{RT},</math>

where {{math|''M''}} is the [[molar mass]], {{math|''P''}} is the pressure, {{math|''R''}} is the [[Gas constant|universal gas constant]], and {{math|''T''}} is the [[absolute temperature]]. This means that the density of an ideal gas can be doubled by doubling the pressure, or by halving the absolute temperature.

In the case of volumic thermal expansion at constant pressure and small intervals of temperature the temperature dependence of density is
<math display="block">\rho = \frac{\rho_{T_0}}{1 + \alpha \cdot \Delta T},</math>

where <math>\rho_{T_0}</math> is the density at a reference temperature, <math>\alpha</math> is the thermal expansion coefficient of the material at temperatures close to <math>T_0</math>.

== Density of solutions ==
The density of a [[Solution (chemistry)|solution]] is the sum of [[mass concentration (chemistry)|mass (massic) concentrations]] of the components of that solution.

Mass (massic) concentration of each given component <math>\rho_i</math> in a solution sums to density of the solution,
<math display=block>\rho = \sum_i \rho_i .</math>

Expressed as a function of the densities of pure components of the mixture and their [[volume concentration|volume participation]], it allows the determination of [[excess molar quantity|excess molar volumes]]:
<math display=block>\rho = \sum_i \rho_i \frac{V_i}{V}\, = \sum_i \rho_i \varphi_i = \sum_i \rho_i \frac{V_i}{\sum_i V_i + \sum_i {V^E}_i},</math>
provided that there is no interaction between the components.

Knowing the relation between excess volumes and activity coefficients of the  components, one can determine the activity coefficients:
<math display=block>\overline{V^E}_i = RT \frac{\partial\ln\gamma_i}{\partial P}.</math>

== List of densities {{anchor|Densities}} ==

=== Various materials ===
{{About|the listing of only certain chemical elements|the densities of all chemical elements|List of chemical elements|section=yes}}

{| class="wikitable sortable" style="text-align:center;"
|+Densities of various materials covering a range of values
|-
! Material
! ''ρ'' (kg/m<sup>3</sup>)<ref group=note>Unless otherwise noted, all densities given are at [[standard conditions for temperature and pressure]],<br>that is, {{convert|273.15|K|C|abbr=on|lk=in}} and {{convert|100|kPa|atm|3|abbr=on}}.</ref>
! class="unsortable" | Notes
|-0.08988
| [[Hydrogen]]                 || 0.0898 ||
|-
| [[Helium]]                   || 0.179  ||
|-
| [[Aerographite]]             || 0.2    || <ref group=note name=noair>Air contained in material excluded when calculating density</ref><ref>[http://phys.org/news/2012-07-carbon-nanotube-struructure-aerographite-lightest.html New carbon nanotube struructure aerographite is lightest material champ] {{webarchive|url=https://web.archive.org/web/20131017064205/http://phys.org/news/2012-07-carbon-nanotube-struructure-aerographite-lightest.html |date=October 17, 2013 }}. Phys.org (July 13, 2012). Retrieved on July 14, 2012.</ref><ref>[http://www.spiegel.de/wissenschaft/technik/aerographit-leichtestes-material-der-welt-entwickelt-a-843819.html Aerographit: Leichtestes Material der Welt entwickelt – SPIEGEL ONLINE] {{webarchive|url=https://web.archive.org/web/20131017083053/http://www.spiegel.de/wissenschaft/technik/aerographit-leichtestes-material-der-welt-entwickelt-a-843819.html |date=October 17, 2013 }}. Spiegel.de (July 11, 2012). Retrieved on July 14, 2012.</ref>
|-
| [[Metallic microlattice]]    || 0.9    || <ref group=note name=noair/>
|-
| [[Aerogel]]                  || 1.0    || <ref group=note name=noair/>
|-
| [[Air]]                      || 1.2    || At sea level
|-
| [[Tungsten hexafluoride]]    || 12.4   || One of the heaviest known gases at standard conditions
|-
| [[Liquid hydrogen]]          || 70     || At approximately −255&nbsp;°C
|-
| [[Styrofoam]]                || 75     || Approximate<ref name="madsci1">{{cite web |url=http://www.madsci.org/posts/archives/mar2000/954534602.Ph.r.html |title=Re: which is more {{sic|bou|yant|nolink=y}} styrofoam or cork |publisher=Madsci.org |access-date=September 14, 2010 |url-status=live |archive-url=https://web.archive.org/web/20110214145901/http://www.madsci.org/posts/archives/mar2000/954534602.Ph.r.html |archive-date=February 14, 2011 |df=mdy-all }}</ref>
|-
| [[Cork (material)|Cork]]     || 240    || Approximate<ref name="madsci1" />
|-
| [[Pine]]                     || 373    || <ref name="SerwayJewett2005">{{citation|first1=Raymond |last1=Serway|first2=John |last2=Jewett|title=Principles of Physics: A Calculus-Based Text|url=https://books.google.com/books?id=VaroJ5BNuZAC|year=2005|publisher=Cengage Learning|isbn=0-534-49143-X|page=467|url-status=live|archive-url=https://web.archive.org/web/20160517053840/https://books.google.com/books?id=VaroJ5BNuZAC|archive-date=May 17, 2016|df=mdy-all}}</ref>
|-
| [[Lithium]]                  || 535    || Least dense metal
|-
| [[Wood]]                     || 700    || Seasoned, typical<ref name=wood0>{{cite web |url=http://www.engineeringtoolbox.com/wood-density-d_40.html |title=Wood Densities |access-date=October 15, 2012 |work=www.engineeringtoolbox.com |url-status=live |archive-url=https://web.archive.org/web/20121020065545/http://www.engineeringtoolbox.com/wood-density-d_40.html |archive-date=October 20, 2012 |df=mdy-all }}</ref><ref name=wood1>{{cite web |title=Density of Wood |url=http://www.simetric.co.uk/si_wood.htm |access-date=October 15, 2012 |work=www.simetric.co.uk |url-status=live |archive-url=https://web.archive.org/web/20121026115734/http://www.simetric.co.uk/si_wood.htm |archive-date=October 26, 2012 |df=mdy-all }}</ref>
|-
| [[Oak]]                      || 710    || <ref name="SerwayJewett2005"/>
|-
| [[Potassium]]                || 860    || <ref name="crc2ed">{{cite book |chapter=§1.3 Solids—Metals: Table 1-59 Metals and Alloys—Miscellaneous Properties |chapter-url=https://books.google.com/books?id=Xn8KbsgeFrwC&pg=PA117 |editor-first=Ray E. |editor-last=Bolz |editor2-first=George L. |editor2-last=Tuve |title=CRC Handbook of tables for Applied Engineering Science |publisher= CRC Press|edition=2nd |date=1970 |isbn=9781315214092 |pages=117 |url=}}</ref> 
|-
| [[Ice]]                      || 916.7  || At temperature <&nbsp;0&nbsp;°C<!-- Sourced from the "Ice" page -->
|-
| [[Cooking oil]]              || 910–930 ||
|-
| [[Sodium]]                   || 970    ||
|-
| [[Water]] (fresh)            || 1,000  || At 4&nbsp;°C, the temperature of its maximum density
|-
| [[Water]] (salt)             || 1,030  || 3%
|-
| [[Liquid oxygen]]            || 1,141  || At approximately −219&nbsp;°C
|-
| [[Nylon]]                    || 1,150  ||
|-
| [[Plastics]]                 || 1,175  || Approximate; for [[polypropylene]] and [[PETE]]/[[PVC]]
|-
| [[Glycerol]]                 || 1,261  || <ref>[http://physics.nist.gov/cgi-bin/Star/compos.pl?matno=174 glycerol composition at] {{webarchive|url=https://web.archive.org/web/20130228142256/http://physics.nist.gov/cgi-bin/Star/compos.pl?matno=174 |date=February 28, 2013 }}. Physics.nist.gov. Retrieved on July 14, 2012.</ref>
|-
| [[Tetrachloroethene]]        || 1,622  ||
|-
| [[Sand]]                      || 1,600 || Between 1,600 and 2,000 <ref name="Sharma1997"/>
|-
| [[Magnesium]]                || 1,740  ||
|-
| [[Beryllium]]                || 1,850  ||
|-
| [[Silicon]]                  || 2,330  ||
|-
| [[Concrete]]                 || 2,400  || <ref>{{Cite web|url=https://hypertextbook.com/facts/1999/KatrinaJones.shtml|title=Density of Concrete - The Physics Factbook|website=hypertextbook.com}}</ref><ref name="YoungFreedman2012">{{cite book |first1=Hugh D. |last1=Young |first2=Roger A. |last2=Freedman |title=University Physics with Modern Physics |publisher=Addison-Wesley |date=2012 |isbn=978-0-321-69686-1 |pages=374 |url=}}</ref>
|-
| [[Glass]]                 || 2,500  || <ref>{{Cite web|url=https://hypertextbook.com/facts/2004/ShayeStorm.shtml|title=Density of Glass - The Physics Factbook|website=hypertextbook.com}}</ref>
|-
| [[Quartzite]]                      || 2,600    || <ref name="Sharma1997"/>
|-
| [[Granite]]                      || 2,700    || <ref name="Sharma1997"/>
|-
| [[Gneiss]]                      || 2,700    || <ref name="Sharma1997"/>
|-
| [[Aluminium]]                || 2,700  ||
|-
| [[Limestone]]                     || 2,750    || Compact<ref name=Sharma1997>{{citation|first=P.V. |last=Sharma|title=Environmental and Engineering Geophysics|year=1997|publisher=Cambridge University Press|isbn= 9781139171168|page=17|doi=10.1017/CBO9781139171168}}</ref>
|-
| [[Basalt]]                      || 3,000    || <ref name="Sharma1997"/>
|-
| [[Diiodomethane]]            || 3,325  || Liquid at room temperature
|-
| [[Diamond]]                  || 3,500  ||
|-
| [[Titanium]]                 || 4,540  ||
|-
| [[Selenium]]                 || 4,800  ||
|-
| [[Vanadium]]                 || 6,100  ||
|-
| [[Antimony]]                 || 6,690  ||
|-
| [[Zinc]]                     || 7,000  ||
|-
| [[Chromium]]                 || 7,200  ||
|-
| [[Tin]]                      || 7,310  ||
|-
| [[Manganese]]                || 7,325  || Approximate
|-
| [[Mild steel]]               || 7,850  ||
|-
| [[Iron]]                     || 7,870  ||
|-
| [[Niobium]]                  || 8,570  ||
|-
| [[Brass]]                    || 8,600  || <ref name="YoungFreedman2012"/>
|-
| [[Cadmium]]                  || 8,650  ||
|-
| [[Cobalt]]                   || 8,900  ||
|-
| [[Nickel]]                   || 8,900  ||
|-
| [[Copper]]                   || 8,940  ||
|-
| [[Bismuth]]                  || 9,750  ||
|-
| [[Molybdenum]]               || 10,220 ||
|-
| [[Silver]]                   || 10,500 ||
|-
| [[Lead]]                     || 11,340 ||
|-
| [[Thorium]]                  || 11,700 ||
|-
| [[Rhodium]]                  || 12,410 ||
|-
| [[Mercury (element)|Mercury]]|| 13,546 ||
|-
| [[Tantalum]]                 || 16,600  ||
|-
| [[Uranium]]                  || 19,100  ||
|-
| [[Tungsten]]                 || 19,300  ||
|-
| [[Gold]]                     || 19,320  ||
|-
| [[Plutonium]]                || 19,840  ||
|-
| [[Rhenium]]                  || 21,020  ||
|-
| [[Platinum]]                 || 21,450  ||
|-
| [[Iridium]]                  || 22,420  ||
|-
| [[Osmium]]                   || 22,570  || Densest natural element on Earth
|}
{{reflist|group=note}}
{{Clear}}

=== Others ===
{| class="wikitable sortable" style="text-align:center;"
|-
! Entity
! ''ρ'' (kg/m<sup>3</sup>)
! class="unsortable" | Notes
|-
| [[Interstellar medium]]  || data-sort-value="0.000000000000000000000000017" | {{val|1.7|e=-26}} || Based on 10{{sup|−5}} hydrogen atoms per cubic centimetre<ref name="JPL interstellar">{{cite web |url=http://interstellar.jpl.nasa.gov/interstellar/probe/introduction/neighborhood.html |title=Our Local Galactic Neighborhood |publisher=NASA |series=Interstellar Probe Project |year=2000 |access-date=2012-08-08 |archive-url=https://web.archive.org/web/20131121061128/http://interstellar.jpl.nasa.gov/interstellar/probe/introduction/neighborhood.html |archive-date=2013-11-21 |url-status=dead }}</ref>
|-
| [[Local Interstellar Cloud]] || data-sort-value="0.0000000000000000000005" | {{val|5|e=-22}} || Based on 0.3 hydrogen atoms per cubic centimetre<ref name="JPL interstellar"/>
|-
| [[Interstellar medium]]  || data-sort-value="0.0000000000000001" | {{val|1.7|e=-16}} || Based on 10{{sup|5}} hydrogen atoms per cubic centimetre<ref name="JPL interstellar"/>
|-
| The [[Earth]]            || 5,515 || Mean density.<ref>{{citation |url=http://www.wolframalpha.com/input/?i=density+of+the+earth |title=Density of the Earth |publisher=wolframalpha.com |url-status=live |archive-url=https://web.archive.org/web/20131017051437/http://www.wolframalpha.com/input/?i=density+of+the+earth |archive-date=October 17, 2013 |df=mdy-all }}</ref>
|-
| [[Earth's inner core]] || 13,000 || Approx., as listed in [[Earth]].<ref>{{citation |url=http://www.wolframalpha.com/input/?i=density+of+earth%27s+core |title=Density of Earth's core |publisher=wolframalpha.com |url-status=live |archive-url=https://web.archive.org/web/20131017051441/http://www.wolframalpha.com/input/?i=density+of+earth%27s+core |archive-date=October 17, 2013 |df=mdy-all }}</ref>
|-
| The core of the [[Sun]]  || 33,000–160,000 || Approx.<ref>{{citation |url=http://www.wolframalpha.com/input/?i=density+of+sun%27s+core |title=Density of the Sun's core |publisher=wolframalpha.com |url-status=live |archive-url=https://web.archive.org/web/20131017051337/http://www.wolframalpha.com/input/?i=density+of+sun%27s+core |archive-date=October 17, 2013 |df=mdy-all }}</ref>
|-
| [[White dwarf]] star     || {{val|2.1|e=9}} || Approx.<ref name="osln">{{cite web |url=http://www.astronomy.ohio-state.edu/~jaj/Ast162/lectures/notesWL22.pdf |title=Extreme Stars: White Dwarfs & Neutron Stars] |archive-url=https://web.archive.org/web/20070925204453/http://www.astronomy.ohio-state.edu/~jaj/Ast162/lectures/notesWL22.pdf |archive-date=2007-09-25 |first=Jennifer |last=Johnson |work=lecture notes, Astronomy 162 |publisher=[[Ohio State University]]}}</ref>
|-
| [[Atomic nuclei]]        || {{val|2.3|e=17}} || Does not depend strongly on size of nucleus<ref>{{cite web |url=http://hyperphysics.phy-astr.gsu.edu/HBASE/Nuclear/nucuni.html |title=Nuclear Size and Density |archive-url=https://web.archive.org/web/20090706034134/http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/nucuni.html |archive-date=2009-07-06 |work=HyperPhysics |publisher=Georgia State University}}</ref>
|-
| [[Neutron star]]         || {{val|1|e=18}} ||
|}

=== Water ===
{{See also|Water (molecule)#Density of water and ice|l1=Water density}}

[[File:Water density metric conversion.png|thumb|Ways of presenting the density of water using five metric units of length, volume, and mass.]]

{| class="wikitable" style="text-align:center;"
|+ Density of liquid water at 1 [[Atmosphere (unit)|atm]] pressure
|-
! Temp. (°C)<ref group=note>Values below 0&nbsp;°C refer to [[supercooling|supercooled]] water.</ref>
! Density (kg/m<sup>3</sup>)
|-
| −30 || 983.854
|-
| −20 || 993.547
|-
| −10 || 998.117
|-
| 0   || 999.8395
|-
| 4   || 999.9720
|-
| 10  || 999.7026
|-
| 15  || 999.1026
|-
| 20  || 998.2071
|-
| 22  || 997.7735
|-
| 25  || 997.0479
|-
| 30  || 995.6502
|-
| 40  || 992.2
|-
| 60  || 983.2
|-
| 80  || 971.8
|-
| 100 || 958.4
|-
|colspan=2 |Notes:
{{reflist|group=note}}
|}

=== Air ===
{{Main article|Density of air}}
[[File:Air density vs temperature.svg|thumb|right|400px|Air density ''vs.'' temperature]]

{| class="wikitable" style="text-align:center;"
|+Density of air at 1 [[Atmosphere (unit)|atm]] pressure
|-
! ''T'' (°C)
! ''ρ'' (kg/m<sup>3</sup>)
|-
| −25 || 1.423
|-
| −20 || 1.395
|-
| −15 || 1.368
|-
| −10 || 1.342
|-
| −5  || 1.316
|-
|  0  || 1.293
|-
|  5  || 1.269
|-
|  10 || 1.247
|-
|  15 || 1.225
|-
|  20 || 1.204
|-
|  25 || 1.184
|-
|  30 || 1.164
|-
|  35 || 1.146
|}
{{Clear}}

=== Molar volumes of liquid and solid phase of elements ===
[[File:Molar volumes of liquid-solid phase of elements.svg|thumb|left|1000px|Molar volumes of liquid and solid phase of elements]]

{{Clear}}

== See also ==
{{Div col|colwidth=22em}}
* [[Densities of the elements (data page)]]
* [[List of elements by density#List|List of elements by density]]
* [[Air density]]
* [[Area density]]
* [[Bulk density]]
* [[Buoyancy]]
* [[Charge density]]
* [[Density current]]
* [[Density gradient]]
* [[Girolami method|Density prediction by the Girolami method]]
* [[Dord]]
* [[Energy density]]
* [[Lighter than air]]
* [[Linear density]]
* [[Number density]]
* [[Orthobaric density]]
* [[Paper density]]
* [[Specific weight]]
* [[Spice (oceanography)]]
* [[Standard temperature and pressure]]
* [[Volumic quantity]]
{{Div col end}}

== References ==
{{Reflist|40em}}

== External links ==
* {{cite EB1911|wstitle=Density |volume=8 |short=x}}
* {{Cite NSRW|wstitle=Density |short=x}}
* [https://www.youtube.com/watch?v=eY-44iPSWIU Video: Density Experiment with Oil and Alcohol]
* [https://www.youtube.com/watch?v=96NFH2Z7GSA Video: Density Experiment with Whiskey and Water]
* [http://glassproperties.com/density/room-temperature/ Glass Density Calculation – Calculation of the density of glass at room temperature and of glass melts at 1000 – 1400°C]
* [https://web.archive.org/web/20080505011613/http://www.science.co.il/PTelements.asp?s=Density List of Elements of the Periodic Table – Sorted by Density]
* [http://ddbonline.ddbst.de/DIPPR105DensityCalculation/DIPPR105CalculationCGI.exe Calculation of saturated liquid densities for some components]
* [http://www.denichsoiltest.com/field/field-density-test.html Field density test] {{Webarchive|url=https://web.archive.org/web/20101215142647/http://www.denichsoiltest.com/field/field-density-test.html |date=December 15, 2010 }}
* [http://www.engineeringtoolbox.com/water-density-specific-weight-d_595.html Water – Density and specific weight]
* [http://www.sengpielaudio.com/ConvDensi.htm Temperature dependence of the density of water – Conversions of density units]
* [http://www.adamequipment.com/education/Documents/EdExp1.pdf A delicious density experiment] {{Webarchive|url=https://web.archive.org/web/20150718024352/http://www.adamequipment.com/education/Documents/EdExp1.pdf |date=July 18, 2015 }}
* [http://linkingweatherandclimate.com/ocean/waterdensitycalc.php Water density calculator] {{Webarchive|url=https://web.archive.org/web/20110713211655/http://www.linkingweatherandclimate.com/ocean/waterdensitycalc.php |date=July 13, 2011 }} Water density for a given salinity and temperature.
* [https://archive.today/20130122123510/http://www.enggcyclopedia.com/welcome-to-enggcyclopedia/calculators/liquid-density Liquid density calculator] Select a liquid from the list and calculate density as a function of temperature.
* [https://archive.today/20130122124432/http://www.enggcyclopedia.com/welcome-to-enggcyclopedia/thermodynamics/gas-density Gas density calculator] Calculate density of a gas for as a function of temperature and pressure.
* [http://www.jaredzone.info/2010/09/densities.html Densities of various materials.]
* [http://amrita.olabs.co.in/?sub=1&brch=1&sim=2&cnt=9 Determination of Density of Solid], instructions for performing classroom experiment.
* {{cite journal |vauthors= Lam EJ, Alvarez MN, Galvez ME, Alvarez EB |title=A model for calculating the density of aqueous multicomponent electrolyte solutions |journal=Journal of the Chilean Chemical Society |volume=53 |issue=1 |pages=1393–8 |date=2008 |doi=10.4067/S0717-97072008000100015 |url=|doi-access=free }}
* {{cite journal |vauthors=Radović IR, Kijevčanin ML, Tasić AŽ, Djordjević BD, Šerbanović SP |title=Derived thermodynamic properties of alcohol+ cyclohexylamine mixtures |journal=Journal of the Serbian Chemical Society |volume=75 |issue=2 |pages=283–293 |date=2010 |doi=10.2298/JSC1002283R |url= |citeseerx=10.1.1.424.3486}}

{{Mole concepts}}
{{Authority control}}

[[Category:Mass density|*]]