Plasma is one of the four fundamental states of matter, was first described by chemist Irving Langmuir in the 1920s. Plasma can be artificially generated by heating or subjecting a neutral gas to a strong electromagnetic field to the point where an ionized gaseous substance becomes electrically conductive, long-range electromagnetic fields dominate the behaviour of the matter. Plasma and ionized gases have properties and display behaviours unlike those of the other states, the transition between them is a matter of nomenclature and subject to interpretation. Based on the surrounding environmental temperature and density ionized or ionized forms of plasma may be produced. Neon signs and lightning are examples of ionized plasma; the Earth's ionosphere is a plasma and the magnetosphere contains plasma in the Earth's surrounding space environment. The interior of the Sun is an example of ionized plasma, along with the solar corona and stars. Positive charges in ions are achieved by stripping away electrons orbiting the atomic nuclei, where the total number of electrons removed is related to either increasing temperature or the local density of other ionized matter.
This can be accompanied by the dissociation of molecular bonds, though this process is distinctly different from chemical processes of ion interactions in liquids or the behaviour of shared ions in metals. The response of plasma to electromagnetic fields is used in many modern technological devices, such as plasma televisions or plasma etching. Plasma may be the most abundant form of ordinary matter in the universe, although this hypothesis is tentative based on the existence and unknown properties of dark matter. Plasma is associated with stars, extending to the rarefied intracluster medium and the intergalactic regions; the word plasma comes from Ancient Greek πλάσμα, meaning'moldable substance' or'jelly', describes the behaviour of the ionized atomic nuclei and the electrons within the surrounding region of the plasma. Each of these nuclei are suspended in a movable sea of electrons. Plasma was first identified in a Crookes tube, so described by Sir William Crookes in 1879; the nature of this "cathode ray" matter was subsequently identified by British physicist Sir J.
J. Thomson in 1897; the term "plasma" was coined by Irving Langmuir in 1928. Lewi Tonks and Harold Mott-Smith, both of whom worked with Irving Langmuir in the 1920s, recall that Langmuir first used the word "plasma" in analogy with blood. Mott-Smith recalls, in particular, that the transport of electrons from thermionic filaments reminded Langmuir of "the way blood plasma carries red and white corpuscles and germs."Langmuir described the plasma he observed as follows: "Except near the electrodes, where there are sheaths containing few electrons, the ionized gas contains ions and electrons in about equal numbers so that the resultant space charge is small. We shall use the name plasma to describe this region containing balanced charges of ions and electrons." Plasma is a state of matter in which an ionized gaseous substance becomes electrically conductive to the point that long-range electric and magnetic fields dominate the behaviour of the matter. The plasma state can be contrasted with the other states: solid and gas.
Plasma is an electrically neutral medium of unbound negative particles. Although these particles are unbound, they are not "free" in the sense of not experiencing forces. Moving charged particles generate an electric current within a magnetic field, any movement of a charged plasma particle affects and is affected by the fields created by the other charges. In turn this governs collective behaviour with many degrees of variation. Three factors define a plasma: The plasma approximation: The plasma approximation applies when the plasma parameter, Λ, representing the number of charge carriers within a sphere surrounding a given charged particle, is sufficiently high as to shield the electrostatic influence of the particle outside of the sphere. Bulk interactions: The Debye screening length is short compared to the physical size of the plasma; this criterion means that interactions in the bulk of the plasma are more important than those at its edges, where boundary effects may take place. When this criterion is satisfied, the plasma is quasineutral.
Plasma frequency: The electron plasma frequency is large compared to the electron-neutral collision frequency. When this condition is valid, electrostatic interactions dominate over the processes of ordinary gas kinetics. Plasma temperature is measured in kelvin or electronvolts and is, informally, a measure of the thermal kinetic energy per particle. High temperatures are needed to sustain ionisation, a defining feature of a plasma; the degree of plasma ionisation is determined by the electron temperature relative to the ionization energy, in a relationship called the Saha equation. At low temperatures and electrons tend to recombine into bound states—atoms—and the plasma will become a gas. In most cases the electrons are close enough to thermal equilibrium that their temperature is well-defined; because of the large difference in ma
The dram is a unit of mass in the avoirdupois system, both a unit of mass and a unit of volume in the apothecaries' system. It was both a coin and a weight in ancient Greece; the unit of volume is more called a fluid dram, fluid drachm, fluidram or fluidrachm. The Attic Greek drachma was a weight of 1⁄100 Greek mina, or about 4.37 grams. The Roman drachma was a weight of 1⁄96 Roman pounds, or about 3.41 grams. A coin weighing one drachma is known as drachm, or drachma; the Ottoman dirhem was based on the Sassanian drachm, itself based on the Roman dram/drachm. The British Weights and Measures Act of 1878 introduced verification and consequent stamping of apothecary weights, making them recognized units of measurement. By 1900, Britain had enforced the distinction between the avoirdupois and apothecaries' versions by making the spelling different: dram now meant only avoirdupois drams, which were 1⁄16 of an avoirdupois ounce of 437.5 grains, thus equal to 27.34 grains drachm now meant only apothecaries' drachms, which were 1⁄8 of an apothecaries' ounce of 480 grains, thus equal to 60 grains In the avoirdupois system, the dram is the mass of 1⁄256 pound or 1⁄16 ounce.
The dram weighs 875⁄32 grains, or 1.7718451953125 grams. In the apothecaries' system, used in the United States until the middle of the 20th century, the dram is the mass of 1⁄96 pounds apothecaries, or 1⁄8 ounces apothecaries; the dram apothecaries is equal to 3 scruples or 60 grains, or 3.8879346 grams."Dram" is used as a measure of the powder charge in a shotgun shell, representing the equivalent of black powder in drams avoirdupois. The fluid dram is defined as 1⁄8 of a fluid ounce, is equal to: 3.6966911953125 ml in the US customary system 3.5516328125 ml in the imperial systemA teaspoonful has been considered equal to one fluid dram for medical prescriptions. However, by 1876 the teaspoon had grown larger than it was measuring 80–85 minims; as there are 60 minims in a fluid dram, using this equivalent for the dosage of medicine was no longer suitable. Today's US teaspoon is equivalent to 1⁄6 US fluid ounces, 1 1⁄3 US fluid drams, or 80 US minims. While pharmaceuticals are measured nowadays in metric units, fluid drams are still used to measure the capacity of pill containers.
Dram is used informally to mean a small amount of spirituous liquor Scotch whisky. The unit is referenced by the phrase dram shop, the US legal term for an establishment that serves alcoholic beverages; the line "Where'd you get your whiskey, where'd you get your dram?" Appears in some versions of the traditional pre-Civil War American song "Cindy". In Monty Python's song entitled The Bruces' Philosophers Song there is the following line: "Hobbes was fond of his dram". In the old-time music tradition of the United States, there is a tune entitled "Gie the Fiddler a Dram". “Gie” being the Scottish dialectal version of give, brought over by immigrants and used by their descendants in Appalachia at the time of writing. In the episode "Double Indecency" of the TV series Archer, the character Cheryl/Carol was carrying around 10 drams of Vole's blood and offered to pay for a taxi ride with it. In Frank Herbert's Dune, the Fremen employ a sophisticated measurement system that involves the drachm to count and economize water, a ultra-precious resource on their home of Arrakis.
Appendix C – General Tables of Units of Measurement in Specifications and Other Technical Requirements for Weighing and Measuring Devices. NIST Handbook 44. Image of Ancient Greek silver drachm with flying Pegasus, Leucas, c. 470–450 BCE
The cup is a unit of volume, most associated with cooking and serving sizes. It is traditionally equal to half a liquid pint in US customary units but is now separately defined in terms of the metric system at values between 1⁄5 and 1⁄4 of a litre; because actual drinking cups may differ from the size of this unit, standard measuring cups are used instead. The cup used in the United States for nutrition labelling is defined in United States law as 240 mL. In the United States, the customary cup is half of a liquid pint. A customary "cup" of coffee in the U. S. is defined as 4 fluid ounces, brewed using 5 fluid ounces of water. Coffee carafes used with drip coffee makers, such as Black and Decker models, have markings for both water and brewed coffee, since the carafe is used for measuring water prior to brewing. A 12-cup carafe, for example, has markings for 4, 6, 8, 10, 12 cups of water or coffee, which correspond to 20, 30, 40, 50, 60 fluid ounces of water or 16, 24, 32, 40, 48 fluid ounces of brewed coffee the difference being the volume lost to evaporation during brewing.
Australia, New Zealand, some other members of the Commonwealth of Nations—being former British colonies that have since metricated—employ a "metric cup" of 250 millilitres. Although derived from the metric system, it is not an SI unit. A "coffee cup" is 1.5 dL or 150 millilitres or 5.07 US customary fluid ounces, is used in recipes. It is used in the US to specify coffeemaker sizes. A "12-cup" US coffeemaker makes 57.6 US customary fluid ounces of coffee, or 6.8 metric cups of coffee. In older recipes cup may mean "coffee cup". Canada now employs the metric cup of 250 mL but its conventional cup was somewhat smaller than both American and imperial units.1 Canadian cup = 8 imperial fluid ounce = 1/20 imperial gallon = 227.3045 millilitres 1 tablespoon = 1/2 imperial fluid ounce 1 teaspoon = 1/6 imperial fluid ounce In the United Kingdom the standard cup was set at 10 imperial fluid ounces, or half an imperial pint. The cup was used in practice, as most kitchens tended to be equipped with scales and ingredients were measured by weight, rather than volume.
Similar units in other languages and cultures are sometimes translated "cup" with various values around 1⁄5 to 1⁄4 of a liter. In Latin America, the amount of a "cup" varies from country to country, with some intending 200 mL, others 250 mL, still others the US legal or customary amount; the traditional Japanese unit equated with a "cup" size is the gō equated with 2401/13310 liters in 1891. It is still used for reckoning amounts of sake. Separately, the Japanese standardized a "cup" defined as 200 mL. Traditional Russian measurement system included two cup sizes, one of which, "charka", was used for alcoholic drinks and measured 123 mL or 4.16 US fl. oz. while another, "stakan" was twice of that or 246 mL/8.32 fl.oz. and used for other liquids. Since metrication, the charka was informally redefined as 100 mL, acquiring a new name of "stopka", while there are two used glass sizes of 250 and 200 mL. In Europe, recipes weigh non-liquid ingredients in grams rather than measuring volume. For example, where an American recipe might specify "1 cup of sugar and 2 cups of milk", a European recipe might specify "200 g sugar and 500 ml of milk".
A precise conversion between the two measures takes into account the density of the ingredients, some recipes specify both weight and volume to facilitate this conversion. Many European measuring cups have markings that indicate the weight of common ingredients for a given volume. Cooking weights and measures
A cubic centimetre is a used unit of volume that extends the derived SI-unit cubic metre, corresponds to the volume of a cube that measures 1 cm × 1 cm × 1 cm. One cubic centimetre corresponds to a volume of 1/1,000,000 of a cubic metre, or 1/1,000 of a litre, or one millilitre; the mass of one cubic centimetre of water at 3.98 °C is equal to one gram. SI deprecates the use of any abbreviations for units. Hence cm3 is preferred to ccm. Many scientific disciplines have replaced cubic centimeter measurements with milliliters, but the medical and automotive fields in the United States still use the term cubic centimetre. Much of the automotive industry outside the U. S. has switched to litres. The United Kingdom uses millilitres in preference to cubic centimetres in the medical field, but not the automotive. Most other English-speaking countries follow the UK example. There is a movement within the medical field to discontinue the use of cc in prescriptions and on medical documents, as it can be misread as "00".
This could cause a hundredfold overdose of medication, which could be dangerous or lethal. In the United States, such confusion accounts for 12.6% of all errors associated with medical abbreviations. In automobile engines, "cc" refers to the total volume of its engine displacement in cubic centimetres; the displacement can be calculated using the formula d = π 4 × b 2 × s × n where d is engine displacement, b is the bore of the cylinders, s is length of the stroke and n is the number of cylinders. Conversions 1 millilitre = 1 cm3 1 litre = 1000 cm3 1 cubic inch = 16.387 cm3. Centimetre Cubic inch Litre
A measuring cup or measuring jug is a kitchen utensil used to measure the volume of liquid or bulk solid cooking ingredients such as flour and sugar for volumes from about 50 mL upwards. Measuring cups are used to measure washing powder, liquid detergents and bleach for clothes washing; the cup will have a scale marked in cups and fractions of a cup, with fluid measure and weight of a selection of dry foodstuffs. Measuring cups may be made of glass, or metal. Transparent cups can be read from an external scale. Measuring cups have capacities from 250 mL to 1000 mL, though larger sizes are available for commercial use, they have scale markings at different heights: the substance being measured is added to the cup until it reaches the wanted level. Dry measure cups without a scale are sometimes used, in sets of 1/4, 1/3, 1/2, 1 cup; the units may be milliliters or fractions of a liter, or the cup with its fractions and fluid ounces. Dry measure cups are distinguished from liquid measure cups in that they are meant to be filled to the top so that excess may be scraped off and shallow for easy cleaning.
Liquid measure cups tend to be microwave safe for heating and clear to more judge the meniscus. Sometimes multiples of teaspoons and tablespoons are included. There may be scales for the approximate weight for particular substances, such as flour and sugar. Many dry ingredients, such as granulated sugar, are not compressible, so volume measures are consistent. Others, notably flour, are more variable. For example, 1 cup of all-purpose flour sifted into a cup and leveled weighs about 100 grams, whereas 1 cup of all-purpose flour scooped from its container and leveled weighs about 140 grams. Using a measuring cup to measure bulk foods which can be compressed to a variable degree such as chopped vegetables or shredded cheese leads to large measurement uncertainties, it is easier to chop down the units for a better measure. Cup Kitchen scale Spoon scale WBUR story on a measuring cup design which keep a perfect ratio of surface area to volume, for consistent accuracy
The gill or teacup is a unit of measurement for volume equal to a quarter of a pint. It is no longer except in regard to the volume of alcoholic spirits measures. In imperial units In United States customary units In Great Britain, the standard single measure of spirits in a pub was 1⁄6 gill in England, 1⁄5 gill in Scotland; the 1⁄4 gill was the most common measure in Scotland, still remains as the standard measure in pubs in Ireland. After metrication this was replaced by 35 ml measures. Half of a gill is so an eighth of a pint, but in northern England, a quarter pint could be called a jack or a noggin rather than a gill, in some areas a half pint could be called a gill for beer and milk. In Ireland, the standard spirit measure was 1⁄4 gill. In the Republic of Ireland, it still retains this value, though it is now specified in metric units as 35.5 ml. In Scotland, there were additional sizes: big gill = 1.5 Imp. gill wee gill = 3/4 Imp. gill wee half gill = 3/8 Imp. gill nip=1/4 Imp. gill There are occasional references to a gill in popular culture, such as in: In L. Frank Baum's The Patchwork Girl of Oz, one of the ingredients required for a magic spell is a gill of water from a dark well.
In chapter 19, the obscure unit is used for humor including a pun with the nursery rhyme "Jack and Jill", which involved a well. In George Orwell's Animal Farm, Moses the Raven is allotted a gill of beer a day after he returns, with the implication that this is part of his payment for supporting the farm leaders, the pigs. Dan Simmons' novel, The Terror, makes frequent references to gills of rum. In Robert Louis Stevenson's Treasure Island there are uses of the measure gill, with Israel Hands drinking a gill of brandy in the chapter'I Strike the Jolly Roger'; the cumulative song "The Barley Mow". In The Doors song "The Crystal Ship", the line, "the crystal ship is being filled a thousand girls," some people report that "girls" should be "gills". A gill is referenced in Archer season 2, episode 3 when Barry explains to Archer that a litre is, "about 8 gills".. In "Bart the Genius," an episode of The Simpsons, a child tricks Bart by offering, "I'll trade you 1,000 picolitres of my milk for four gills of yours."
Because of its more used homograph, gill is mispronounced with a hard'g' sound. FX's animated cartoon Archer, mispronounced gill in the episodes "Blood Test" and "Heart of Archness: Part Three". Television host Stephen Fry mispronounced gill in a 2013 edition of the BBC TV programme QI
Solid is one of the four fundamental states of matter. In solids particles are packed, it is characterized by structural resistance to changes of shape or volume. Unlike liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire volume available to it like a gas does; the atoms in a solid are bound to each other, either in a regular geometric lattice or irregularly. Solids cannot be compressed with little pressure whereas gases can be compressed with little pressure because in gases molecules are loosely packed; the branch of physics that deals with solids is called solid-state physics, is the main branch of condensed matter physics. Materials science is concerned with the physical and chemical properties of solids. Solid-state chemistry is concerned with the synthesis of novel materials, as well as the science of identification and chemical composition; the atoms, molecules or ions that make up solids may be arranged in an orderly repeating pattern, or irregularly.
Materials whose constituents are arranged in a regular pattern are known as crystals. In some cases, the regular ordering can continue unbroken over a large scale, for example diamonds, where each diamond is a single crystal. Solid objects that are large enough to see and handle are composed of a single crystal, but instead are made of a large number of single crystals, known as crystallites, whose size can vary from a few nanometers to several meters; such materials are called polycrystalline. All common metals, many ceramics, are polycrystalline. In other materials, there is no long-range order in the position of the atoms; these solids are known as amorphous solids. Whether a solid is crystalline or amorphous depends on the material involved, the conditions in which it was formed. Solids that are formed by slow cooling will tend to be crystalline, while solids that are frozen are more to be amorphous; the specific crystal structure adopted by a crystalline solid depends on the material involved and on how it was formed.
While many common objects, such as an ice cube or a coin, are chemically identical throughout, many other common materials comprise a number of different substances packed together. For example, a typical rock is an aggregate of several different minerals and mineraloids, with no specific chemical composition. Wood is a natural organic material consisting of cellulose fibers embedded in a matrix of organic lignin. In materials science, composites of more than one constituent material can be designed to have desired properties; the forces between the atoms in a solid can take a variety of forms. For example, a crystal of sodium chloride is made up of ionic sodium and chlorine, which are held together by ionic bonds. In diamond or silicon, the atoms share form covalent bonds. In metals, electrons are shared in metallic bonding; some solids most organic compounds, are held together with van der Waals forces resulting from the polarization of the electronic charge cloud on each molecule. The dissimilarities between the types of solid result from the differences between their bonding.
Metals are strong and good conductors of both electricity and heat. The bulk of the elements in the periodic table, those to the left of a diagonal line drawn from boron to polonium, are metals. Mixtures of two or more elements in which the major component is a metal are known as alloys. People have been using metals for a variety of purposes since prehistoric times; the strength and reliability of metals has led to their widespread use in construction of buildings and other structures, as well as in most vehicles, many appliances and tools, road signs and railroad tracks. Iron and aluminium are the two most used structural metals, they are the most abundant metals in the Earth's crust. Iron is most used in the form of an alloy, which contains up to 2.1% carbon, making it much harder than pure iron. Because metals are good conductors of electricity, they are valuable in electrical appliances and for carrying an electric current over long distances with little energy loss or dissipation. Thus, electrical power grids rely on metal cables to distribute electricity.
Home electrical systems, for example, are wired with copper for its good conducting properties and easy machinability. The high thermal conductivity of most metals makes them useful for stovetop cooking utensils; the study of metallic elements and their alloys makes up a significant portion of the fields of solid-state chemistry, materials science and engineering. Metallic solids are held together by a high density of shared, delocalized electrons, known as "metallic bonding". In a metal, atoms lose their outermost electrons, forming positive ions; the free electrons are spread over the entire solid, held together by electrostatic interactions between the ions and the electron cloud. The large number of free electrons gives metals their high values of electrical and thermal conductivity; the free electrons prevent transmission of visible light, making metals opaque and lustrous. More advanced models of metal properties consider the effect of the positive ions cores on the delocalised electrons.
As most metals have crystalline structure, those ions are arranged into a periodic lattice. Mathematically, the potential of the ion cores can be treated by various models, the simplest being the nearly free electron model. Minerals are