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In physics, the triple point of a substance is the temperature and pressure at which three phases (gas, liquid, and solid) of that substance may coexist in thermodynamic equilibrium. Fig. ...
The use of water pressure - the Captain Cook Memorial Jet in Lake Burley Griffin, Canberra. ...
In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ...
A gas is one of the five main phases of matter (after solid and liquid, and followed by plasma and Bose-Einstein Condensate) and, that subsequently appear as a solid material is subjected to increasingly higher temperatures. ...
A liquid will usually assume the shape of its container. ...
In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ...
Thermodynamics (from the Greek thermos meaning heat and dynamics meaning power) is a branch of physics that studies the effects of changes in temperature, pressure, and volume on physical systems at the macroscopic scale by analyzing the collective motion of their particles using statistics. ...
For example, the triple point temperature of mercury is at -38.8344 °C, at a pressure of 0.2 mPa. General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery white Atomic mass 200. ...
The triple point of water is used to define the kelvin, the SI unit of thermodynamic temperature. The number given for the temperature of the triple point of water is an exact definition rather than a measured quantity. The Kelvin scale is a thermodynamic (absolute) temperature scale where absolute zero—the lowest possible temperature where nothing could be colder and no heat energy remains in a substance—is defined as zero kelvin (0 K). ...
Cover of brochure The International System of Units. ...
Triple point of water The single combination of pressure and temperature at which pure water, pure ice, and pure water vapour can coexist in a stable equilibrium occurs at exactly 273.16 kelvins (0.01 °C) and a pressure of 611.73 pascals (ca. 6.1173 millibars, 0.0060373057 atm). At that point, it is possible to change all of the substance to ice, water, or vapour by making infinitesimally small changes in pressure and temperature. Strictly speaking, the surfaces separating the different phases should also be perfectly flat, to avoid the effects of surface tensions. Image File history File links Phase-diag. ...
Image File history File links Phase-diag. ...
Water is a tasteless, odourless substance that is essential to all known forms of life and is known as the universal solvent. ...
Water is a tasteless, odourless substance that is essential to all known forms of life and is known as the universal solvent. ...
To meet Wikipedias quality standards, this article or section may require cleanup. ...
Boundaries: Phase, Pressure, Temperature Evaporation/Sublimation Whenever a water molecule leaves a surface, it is said to have evaporated. ...
The Kelvin scale is a thermodynamic (absolute) temperature scale where absolute zero—the lowest possible temperature where nothing could be colder and no heat energy remains in a substance—is defined as zero kelvin (0 K). ...
The pascal (symbol Pa) is the SI unit of pressure. ...
The bar (symbol bar) and the millibar (symbol mbar, also mb) are units of pressure. ...
When expressed as a measurement, an atmosphere (symbol: atm) or standard atmosphere is a unit of pressure roughly equal to the average atmospheric pressure at sea level on Earth. ...
Water has an unusual and complex phase diagram, although this does not affect general comments about the triple point. At high temperatures, increasing pressure results in first liquid, and then solid, water (above around 109 Pa a crystalline form of ice which is denser than water forms). At lower temperatures the liquid state ceases to appear with compression causing the state to pass directly from gas to solid. In physical chemistry and materials science, a phase diagram is a type of graph used to show the equilibrium conditions between the thermodynamically-distinct phases. ...
At a constant pressure higher than the triple point, heating ice necessarily passes from ice to liquid then to steam. In pressures below the triple point, such as in outer space where the pressure is low, liquid water cannot exist: Ice skips the liquid stage and becomes steam on heating, in a process known as sublimation. In physical chemistry, and in engineering, steam refers to vaporized water. ...
Layers of Atmosphere - not to scale (NOAA) Outer space, also simply called space, refers to the relatively empty regions of the universe outside the atmospheres of celestial bodies. ...
Sublimation of an element or substance is a conversion between the solid and the gas phases with no intermediate liquid stage. ...
Triple point cells are useful in the calibration of thermometers. For exacting work, triple point cells are typically filled with a highly pure chemical substance such as hydrogen, argon, mercury, or water (depending on the desired temperature). The purity of these substances can be such that only one part in a million is a contaminant; what is called “six-nines" because it is 99.9999% pure. When it is a water-based cell, a special isotopic composition called VSMOW water is used because it is considered to be representative of “average ocean water” and produces temperatures that are more comparable from lab to lab. Triple point cells are so effective at achieving highly precise, reproducible temperatures, an international calibration standard for thermometers called ITS–90 relies upon triple point cells for delineating six of its defined temperature points. Calibration refers to the process of setting the magnitude of the output (or response) of a measuring instrument to the magnitude of the input property or attribute within specified accuracy and precision. ...
A common thermometer A thermometer is a device which measures temperature or temperature gradient, using a variety of different principles. ...
Isotopes are any of the several different forms of an element each having different atomic mass. ...
// Overview of VSMOW VSMOW, or Vienna Standard Mean Ocean Water, is a standard defined in 1968 by the International Atomic Energy Agency. ...
The International Temperature Scale of 1990 (ITS-90) is an equipment calibration standard for making measurements on the kelvin and Celsius temperature scales. ...
The zero-elevation or "sea level" of Mars is defined by the height at which the atmospheric pressure corresponds to the triple point of water. Note: This article contains special characters. ...
See also In physical chemistry, thermodynamics, chemistry and condensed matter physics, a critical point, also called a critical state, specifies the conditions (temperature, pressure) at which the liquid state of the matter ceases to exist. ...
It has been suggested that this article or section be merged with Gibbs phase rule. ...
The International Temperature Scale of 1990 (ITS-90) is an equipment calibration standard for making measurements on the kelvin and Celsius temperature scales. ...
In physics and thermodynamics, an equation of state is a constitutive equation describing the state of matter under a given set of physical conditions. ...
// Overview of VSMOW VSMOW, or Vienna Standard Mean Ocean Water, is a standard defined in 1968 by the International Atomic Energy Agency. ...
This article or section does not cite its references or sources. ...
External links - Definition of the kelvin at BIPM
- Phase diagram of water
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