Editing Melting point (section)

==Examples==
{{further|List of elements by melting point}}
[[File: Carboxylic.Acids.Melting.&.Boiling.Points.jpg|thumb|upright=1.3|Melting points (in blue) and boiling points (in pink) of the first eight [[carboxylic acids]] (°C)]]

For most substances, [[melting]] and [[freezing]] points are approximately equal. For example, the melting and freezing points of [[mercury (element)|mercury]] is {{Convert|234.32|K|C F|lk=on|abbr=out}}.<ref>[[#Haynes|Haynes]], p. 4.122.</ref> However, certain substances possess differing solid-liquid transition temperatures. For example, [[agar]] melts at {{Convert|85|C|F K}} and solidifies from {{Convert|31|C|F K}}; such direction dependence is known as [[hysteresis]]. The melting point of ice at 1 atmosphere of pressure is very close<ref>The melting point of purified water has been measured as 0.002519 ± 0.000002 °C, see {{cite journal|author1=Feistel, R. |author2=Wagner, W. |name-list-style=amp |year = 2006 |title = A New Equation of State for H<sub>2</sub>O Ice Ih |journal = Journal of Physical and Chemical Reference Data|volume = 35|issue = 2 |pages = 1021–1047 |doi = 10.1063/1.2183324|bibcode = 2006JPCRD..35.1021F }}</ref> to {{Convert|0|C|F K}}; this is also known as the ice point. In the presence of [[Nucleation|nucleating substances]], the freezing point of water is not always the same as the melting point. In the absence of nucleators water can exist as a [[Supercooling|supercooled]] liquid down to {{Convert|-48.3|C|F K}} before freezing.<ref>{{Cite journal |last1=Kringle |first1=Loni |last2=Thornley |first2=Wyatt A. |last3=Kay |first3=Bruce D. |last4=Kimmel |first4=Greg A. |date=2020-09-18 |title=Reversible structural transformations in supercooled liquid water from 135 to 245 K |url=https://www.science.org/doi/10.1126/science.abb7542 |journal=Science |language=en |volume=369 |issue=6510 |pages=1490–1492 |doi=10.1126/science.abb7542 |pmid=32943523 |issn=0036-8075|arxiv=1912.06676 |bibcode=2020Sci...369.1490K }}</ref>

The metal with the highest melting point is [[tungsten]], at {{Convert|3414|C|F K}};<ref>[[#Haynes|Haynes]], p. 4.123.</ref> this property makes tungsten excellent for use as [[electrical filament]]s in [[incandescent lamp]]s. The often-cited [[carbon]] does not melt at ambient pressure but [[sublimation (physics)|sublimes]] at about {{Convert|3700|C|F K|sigfig=2}}; a liquid phase only exists above pressures of {{Convert|10|MPa|atm|abbr=on}} and estimated {{Convert|4,030-4,430|C|F K}} (see [[:File:Carbon-phase-diagramp.svg|carbon phase diagram]]). [[Hafnium carbonitride]] (HfCN) is a [[refractory]] compound with the highest known melting point of any substance to date and the only one confirmed to have a melting point above {{Convert|4273|K|C F}} at ambient pressure. Quantum mechanical computer simulations predicted that this alloy (HfN<sub>0.38</sub>C<sub>0.51</sub>) would have a melting point of about 4,400 K.<ref>{{cite journal|author1= Hong, Q.-J. |author2=van de Walle, A. |year = 2015 | title = Prediction of the material with highest known melting point from ab initio molecular dynamics calculations | journal = Phys. Rev. B | volume = 92 |issue = 2 | pages = 020104(R) | doi = 10.1103/PhysRevB.92.020104 |bibcode=2015PhRvB..92b0104H |doi-access = free }}</ref> This prediction was later confirmed by experiment, though a precise measurement of its exact melting point has yet to be confirmed.<ref>{{cite journal |last1=Buinevich |first1=V.S. |last2=Nepapushev |first2=A.A. |last3=Moskovskikh |first3=D.O. |last4=Trusov |first4=G.V. |last5=Kuskov |first5=K.V. |last6=Vadchenko |first6=S.G. |last7=Rogachev |first7=A.S. |last8=Mukasyan |first8=A.S. |title=Fabrication of ultra-high-temperature nonstoichiometric hafnium carbonitride via combustion synthesis and spark plasma sintering |journal=Ceramics International |date=March 2020 |volume=46 |issue=10 |pages=16068–16073 |doi=10.1016/j.ceramint.2020.03.158 |s2cid=216437833 }}</ref>  At the other end of the scale, [[helium]] does not freeze at all at normal pressure even at temperatures arbitrarily close to [[absolute zero]]; a pressure of more than twenty times normal [[atmospheric pressure]] is necessary.

{| class="wikitable sortable collapsible"
! colspan=4 |List of common chemicals
|-
!Chemical{{efn-ur|name=fn10}}
! data-sort-type="number" | [[Density]] {{nowrap|1=({{nobold|1={{sfrac|[[Gram|g]]|[[Cubic centimetre|cm<sup>3</sup>]]}}}})}}
! data-sort-type="number" | Melt {{nowrap|1=({{nobold|[[Kelvin|K]]}})}}<ref>{{cite journal|last1=Holman|first1=S. W.|last2=Lawrence|first2=R. R.|last3=Barr|first3=L.|title=Melting Points of Aluminum, Silver, Gold, Copper, and Platinum|journal=Proceedings of the American Academy of Arts and Sciences|date=1 January 1895|volume=31|pages=218–233|doi=10.2307/20020628|jstor=20020628}}</ref> 
! data-sort-type="number" | [[Boiling point|Boil]] {{nowrap|1=({{nobold|K}})}}
|-
| Water @STP || 1 || {{convert|0|C|K|disp=number}} || {{convert|100|C|K|disp=number}}
|-
| [[Solder]] (Pb60Sn40) ||   || {{convert|188|C|K|disp=number}} || 
|-
| [[Cocoa butter]] || || {{convert|34.1|C|K|disp=number}} || -
|-
| [[Paraffin wax]] || 0.9 || {{convert|37|C|K|disp=number}} || {{convert|370|C|K|disp=number}}
|-
| [[Hydrogen]] || 0.00008988 || {{sort|0014|14.01}} || 20.28
|-
| [[Helium]] || 0.0001785 || {{sort|0.1|—}}{{efn-ur|name=fn6}} || 4.22
|-
| [[Beryllium]] || 1.85 || {{sort|1560|1,560}} || 2,742
|-
| [[Carbon]] || 2.267 || {{sort|0.1|—}}{{efn-ur|name=fn11}}<ref name=rsc/> || 4,000{{efn-ur|name=fn11}}<ref name=rsc>{{cite web|url=https://www.rsc.org/periodic-table/element/6/carbon|title=Carbon|website=rsc.org}}</ref>
|-
| [[Nitrogen]] || 0.0012506 || {{sort|0063|63.15}} || 77.36
|-
| [[Oxygen]] || 0.001429 || {{sort|0054|54.36}} || 90.20
|-
| [[Sodium]] || 0.971 || {{sort|0371|370.87}} || 1,156
|-
| [[Magnesium]] || 1.738 || {{sort|0923|923}} || 1,363
|-
| [[Aluminium]] || 2.698 || {{sort|0933.5|933.47}} || 2,792
|-
| [[Sulfur]] || 2.067 || {{sort|0388.4|388.36}} || 717.87
|-
| [[Chlorine]] || 0.003214 || {{sort|0171.6|171.6}} || 239.11
|-
| [[Potassium]] || 0.862 || {{sort|0336.5|336.53}} || 1,032
|-
| [[Titanium]] || 4.54 || {{sort|1941|1,941}} || 3,560
|-
| [[Iron]] || 7.874 || {{sort|1811|1,811}} || 3,134
|-
| [[Nickel]] || 8.912 || {{sort|1728|1,728}} || 3,186
|-
| [[Copper]] || 8.96 || 1,357.77 || 2,835
|-
| [[Zinc]] || 7.134 || {{sort|0693|692.88}} || 1,180
|-
| [[Gallium]] || 5.907 || {{sort|0302.9|302.9146}} || 2,673
|-
| [[Silver]] || 10.501 || 1,234.93 || 2,435
|-
| [[Cadmium]] || 8.69 || {{sort|0594.22|594.22}} || 1,040
|-
| [[Indium]] || 7.31 || {{sort|0429.75|429.75}} || 2,345
|-
| [[Iodine]] || 4.93 || {{sort|0386.85|386.85}} || 457.4
|-
| [[Tantalum]] || 16.654 || 3,290 || 5,731
|-
| [[Tungsten]] || 19.25 || 3,695 || 5,828
|-
| [[Platinum]] || 21.46 || 2,041.4 || 4,098
|-
| [[Gold]] || 19.282 || 1,337.33 || 3,129
|-
| [[Mercury (element)|Mercury]] || 13.5336 || {{sort|0234.43|234.43}} || 629.88
|-
| [[Lead]] ||  11.342 || {{sort|0600.61|600.61}} || 2,022
|-
| [[Bismuth]] || 9.807 || {{sort|0544.7|544.7}} || 1,837
|-
|- class="sortbottom"
| colspan=13 |<div class="mw-collapsible mw-collapsed">
Notes<!-- Footnotes are defined here -->
<div class="mw-collapsible-content">{{notelist|group=upper-roman|refs=
{{efn-ur|name=fn6|Helium does not solidify at a pressure of one atmosphere. Helium can only solidify at pressures above 25 atmospheres, which corresponds to a melting point of absolute zero.}}
{{efn-ur|name=fn10|Z is the standard symbol for [[atomic number]]; C is the standard symbol for [[heat capacity]]; and χ is the standard symbol for [[electronegativity]] on the Pauling scale.}}
{{efn-ur|name=fn11|Carbon does not melt at any temperature under standard pressure, instead it sublimes around 4,100 K}}
}}</div></div>
|}