All Words Glossary

Glossary of Chemistry Terms
beginning with letter P
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P Tweet Definition of P Like Definition of P on Facebook
  1. The sixteenth letter of the Appendix:Roman script, English alphabet, preceded by O and followed by Q.
  1. Park
  2. Phone
  3. Pager
  4. Passenger
palladium Tweet Definition of palladium Like Definition of palladium on Facebook
noun (countable and uncountable; pluralpalladiaor )
  1. (countable) a safeguard (from a statue of Athena that was believed to safeguard the ancient city of Troy).
  2. (uncountable) a metallic chemical element (symbol Pd) with an atomic number of 46.
palmitic acid Tweet Definition of palmitic acid Like Definition of palmitic acid on Facebook
  1. (fatty acid) One of the most common saturated fatty acids; it is found in all animal and most vegetable oils and fats; it is used in the manufacture of soap etc.
  2. (organic compound) hexadecanoic acid, CH3(CH2)14COOH
para Tweet Definition of para Like Definition of para on Facebook
  1. Formerly, one-hundredth of a dinar in Yugoslavia and, later, in the constituent states of that country.
paraffin Tweet Definition of paraffin Like Definition of paraffin on Facebook
  1. a petroleum based thin and colorless fuel oil, (kerosine in US English.)
  1. (chemistry) any member of the alkane hydrocarbons
  2. paraffin wax
paraffin wax Tweet Definition of paraffin wax Like Definition of paraffin wax on Facebook
  1. A waxy white solid hydrocarbon mixture used to make candles, wax paper, lubricants, and sealing materials
parent compound Tweet Definition of parent compound Like Definition of parent compound on Facebook
  1. (chemistry) The simplest member of a class of compounds, from which the others are formally obtained by substituting radicals for hydrogen atoms.
particulate Tweet Definition of particulate Like Definition of particulate on Facebook
  1. any solid or liquid in a subdivided state, especially one that exhibits special characteristics which are negligible in the bulk material
Particulates in engine oil can abrade moving parts.
  1. any solid or liquid suspended in air or free to suspend in air
  1. comprise, Comprised of particles; as, particulate matter.
passive Tweet Definition of passive Like Definition of passive on Facebook
  1. Something that is not active, but rather is acted upon.
  2. (grammar) When the subject of a sentence has an action done to them.
    The form of "A meteorite hit the earth" is "The earth was hit by a meteorite."
  3. (slang) Remaining neutral or submissive during an event.
    He remained during the protest.
PBB Tweet Definition of PBB Like Definition of PBB on Facebook
  1. polybrominated biphenyl
PCB Tweet Definition of PCB Like Definition of PCB on Facebook
  1. (electronics) printed circuit board, also called electronics board.
  2. (organic chemistry) polychlorinated biphenyl.
  3. (context, informatics) program control block.
PD Tweet Definition of PD Like Definition of PD on Facebook
  1. Police Department
  1. (electronics) Phase Detector.
  2. (Ireland) w:Progressive Democrats, Progressive Democrats (Political party)
PDB Tweet Definition of PDB Like Definition of PDB on Facebook
  1. President's Daily Briefing
  2. Protein Data Bank
pectic acid Tweet Definition of pectic acid Like Definition of pectic acid on Facebook
  1. an acidic derivative of a carbohydrate; the active constituent of pectin
  1. (chemistry) a helical polymer of ~+mn~D-galacturonic acid
pelargonic acid Tweet Definition of pelargonic acid Like Definition of pelargonic acid on Facebook
  1. (chemistry) an aliphatic carboxylic acid, CH3(CH2)7COOH, nonanoic acid, used in the manufacture of plastics, pharmaceuticals etc
pentad Tweet Definition of pentad Like Definition of pentad on Facebook
  1. a group or series of five things
pentavalent Tweet Definition of pentavalent Like Definition of pentavalent on Facebook
  1. (chemistry) having a valence of 5
pentose Tweet Definition of pentose Like Definition of pentose on Facebook
  1. (carbohydrate) A sugar or saccharide containing five carbon atoms.
Ribose, found in RNA, is a common
pentoxide Tweet Definition of pentoxide Like Definition of pentoxide on Facebook
  1. (chemistry) any oxide containing five oxygen atoms in each molecule
perchlorate Tweet Definition of perchlorate Like Definition of perchlorate on Facebook
  1. (chemistry) any salt of perchloric acid; used in pyrotechnics and as powerful oxidizing agents
perchloric acid Tweet Definition of perchloric acid Like Definition of perchloric acid on Facebook
  1. A clear colourless liquid; a strong acid and a violent, sometimes explosive, oxidizing agent
  2. (chemistry) HClO?4, the oxyacid of chlorine in which chlorine has the highest oxidation number
perchloride Tweet Definition of perchloride Like Definition of perchloride on Facebook
  1. (chemistry) A chloride having a higher proportion of chlorine than any other chloride of the same substance or series.
periodate Tweet Definition of periodate Like Definition of periodate on Facebook
  1. A salt of periodic acid.
periodic acid Tweet Definition of periodic acid Like Definition of periodic acid on Facebook
noun (uncountable)
  1. (chemistry) HIO4, the oxyacid of iodine in which iodine has the highest oxidation number; it is a white crystalline substance, and a strong oxidizing agent
periodic table Tweet Definition of periodic table Like Definition of periodic table on Facebook
  1. (chemistry) A tabular chart of the chemical elements according to their atomic numbers so that elements with similar properties are in the same column.

Supplemental Details:

Periodic Table- A grid containing all the known elements on earth. The table was originally designed by Dimitri Mendeleev, in 1869. The grid lists elements by atomic number and atomic weight, in increasing order from left to right then down to the next row. Additionally the elements are grouped by their chemical properties in columns within the grid. The resulting grid, the Periodic Table, uses different rules for rows than columns and results in a grid where the 1st row contains 16 fewer columns than rows 4 thru 7. While the second and third rows have 10 empty columns.

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permanganate Tweet Definition of permanganate Like Definition of permanganate on Facebook
  1. (chemistry) any salt of permanganic acid, they are purple crystalline solids, mostly soluble in water; they are strong oxidizing agents
  2. (chemistry) potassium permanganate
permanganic acid Tweet Definition of permanganic acid Like Definition of permanganic acid on Facebook
  1. (chemistry) the acid, HMnO?4, known only as its salts, the permanganates
Pet. Tweet Definition of Pet. Like Definition of Pet. on Facebook
abbreviation (infl, en, abbreviation)
  1. (biblical) An abbreviation used for the epistles of Peter, books of the New Testament in the Bible.
petrochemical Tweet Definition of petrochemical Like Definition of petrochemical on Facebook
  1. (chemistry) any compound derived from petroleum or natural gas
  1. Of or pertaining to the such compounds, or the industry that produces them
petrochemistry Tweet Definition of petrochemistry Like Definition of petrochemistry on Facebook
  1. (chemistry) tha branch of chemistry that deals with petroleum, natural gas and their derivatives
petrol Tweet Definition of petrol Like Definition of petrol on Facebook
  1. (New Zealand) abbreviation of petroleum, a fluid consisting of a mixture of refined petroleum hydrocarbons, primarily consisting of octane, and commonly used as a motor fuel.
petroleum Tweet Definition of petroleum Like Definition of petroleum on Facebook
noun (pl=petroleums or, rarely, petrolea)
  1. A flammable liquid ranging in color from clear to very dark brown and black, consisting mainly of hydrocarbons, occurring naturally in deposits under earth surface.
PH Tweet Definition of PH Like Definition of PH on Facebook
  1. Philippines
  2. public house
  3. Penthouse
  4. Preliminary Hearing
phase Tweet Definition of phase Like Definition of phase on Facebook
  1. That which is exhibited to the eye; the appearance which anything manifests, especially any one among different and varying appearances of the same object.
  2. Any appearance or aspect of an object of mental apprehension or view
The problem has many phases.
  1. (astronomy) A particular appearance or state in a regularly recurring cycle of changes with respect to quantity of illumination or form, or the absence, of its enlightened disk; as, the phases of the moon or planets. Illustrated in W:Lunar phase, Wikipedia's article Lunar phase.
  2. Any one point or portion in a recurring series of changes, as in the changes of motion of one of the particles constituting a wave or vibration; one portion of a series of such changes, in distinction from a contrasted portion, as the portion on one side of a position of equilibrium, in contrast with that on the opposite side.
verb (phas, ing)
  1. (to phase out) To discontinue (doing) something over a period of time (i.e., in phases).
  2. (transitive) To stun or shock someone.
  3. (intransitive) To become stunned or shocked.
phase diagram Tweet Definition of phase diagram Like Definition of phase diagram on Facebook
  1. (physics),(chemistry) a graph, with axes representing temperature and pressure, showing the equilibrium conditions for a given substance to be a solid, liquid or gas
  2. a similar diagram for a binary mixture of substances, with axes representing composition and temperature
phase rule Tweet Definition of phase rule Like Definition of phase rule on Facebook
noun (wikipedia, Gibbs' phase rule)
  1. (physics) the rule which states that the number of degrees of freedom in a system at equilibrium equals the number of components minus the number of phases plus 2
phenanthrene Tweet Definition of phenanthrene Like Definition of phenanthrene on Facebook
  1. (organic compound) A tricyclic aromatic hydrocarbon obtained from coal tar; used in the manufacture of dyes, pharmaceuticals and explosives; it is isomeric with anthracene.
phenazine Tweet Definition of phenazine Like Definition of phenazine on Facebook
  1. (chemistry) any of a class of aromatic tricyclic heterocycles used to make dyestuffs
phenol Tweet Definition of phenol Like Definition of phenol on Facebook
  1. (organic compound) A caustic, poisonous, white crystalline compound, C6H5OH, derived from benzene and used in resins, plastics, and pharmaceuticals and in dilute form as a disinfectant and antiseptic; once called carbolic acid.
  2. (organic chemistry) Any of a class of aromatic organic compounds having at least one hydroxyl group attached directly to the benzene ring.
phenolate Tweet Definition of phenolate Like Definition of phenolate on Facebook
  1. (chemistry) phenoxide
phenoxide Tweet Definition of phenoxide Like Definition of phenoxide on Facebook
  1. (chemistry) any metallic salt of a phenol
phenyl Tweet Definition of phenyl Like Definition of phenyl on Facebook
  1. (organic compound) A hydrocarbon radical (C6H5) regarded as the essential residue of benzene, and the basis of an immense number of aromatic derivatives.
phlogiston Tweet Definition of phlogiston Like Definition of phlogiston on Facebook
  1. (context, chemistry, historical) The hypothetical fiery principle formerly assumed to be a necessary constituent of combustible bodies and to be given up by them in burning.
phosgene Tweet Definition of phosgene Like Definition of phosgene on Facebook
  1. (inorganic compound) (alternative form of, carbonyl chloride)
    • 2006, Thomas Pynchon, Against the Day, Vintage 2007, p. 265:
    • :""Poison gas"?" A new one on Lew. But Dr. De Bottle had taken on a somber look. "Phosgene."
phosphatic Tweet Definition of phosphatic Like Definition of phosphatic on Facebook
  1. of, relating to, or composed of phosphate
phosphatize Tweet Definition of phosphatize Like Definition of phosphatize on Facebook
verbto phosphatize
  1. to convert something into a phosphate
  2. to treat something with phosphate or phosphoric acid
phosphide Tweet Definition of phosphide Like Definition of phosphide on Facebook
  1. (chemistry) Any binary compound of phosphorus, especially one in oxidation state −3.
phosphine Tweet Definition of phosphine Like Definition of phosphine on Facebook
  1. (chemistry, uncountable) a toxic gas; hydride of phosphorus, PH3
  2. (chemistry, countable) any alkyl or aryl derivative of this compound, PR3 (where at least one R is not H)
phosphite Tweet Definition of phosphite Like Definition of phosphite on Facebook
  1. (chemistry) any salt or ester of phosphorous acid
  2. (chemistry) the anion PO33-, or the trivalent radical PO3
phosphonium Tweet Definition of phosphonium Like Definition of phosphonium on Facebook
  1. (chemistry) the univalent H4P+ cation, derived from phosphane
phosphorate Tweet Definition of phosphorate Like Definition of phosphorate on Facebook
verbto phosphorate
  1. to combine or treat with phosphorus; to phosphorize
phosphoric Tweet Definition of phosphoric Like Definition of phosphoric on Facebook
  1. (chemistry) Of or pertaining to phosphorus.
  2. Resembling phosphorus.
  3. (chemistry) Of a compound, containing phosphorus in a higher oxidation number than phosphorous compounds, especially with one of 5.
phosphoric acid Tweet Definition of phosphoric acid Like Definition of phosphoric acid on Facebook
  1. (inorganic compound) A colourless liquid, H3PO4, used in the manufacture of fertilizers, detergents and pharmaceuticals and as an additive in cola drinks.
phosphorize Tweet Definition of phosphorize Like Definition of phosphorize on Facebook
verbto phosphorize
  1. to combine or treat with phosphorus; to phosphorate
phosphorous Tweet Definition of phosphorous Like Definition of phosphorous on Facebook
  1. (chemistry) Of or pertaining to phosphorus.
  2. Resembling phosphorus.
  3. (chemistry) Of relating to or containing trivalent phosphorus.
phosphorous acid Tweet Definition of phosphorous acid Like Definition of phosphorous acid on Facebook
  1. (chemistry) a yellowish hygroscopic solid, H3PO3; a mild reducing agent
Phosphorus Tweet Definition of Phosphorus Like Definition of Phosphorus on Facebook
proper noun (or Phosphor)
  1. A name sometimes used for Hesperus, the personification in Greek mythology of the planet Venus.
  2. An ancient Greek name for the morning star (the planet Venus when it is visible in the eastern sky before sunrise).
phosphorus pentoxide Tweet Definition of phosphorus pentoxide Like Definition of phosphorus pentoxide on Facebook
  1. (chemistry) the compound, P2O5, formed by the spontaneous combustion of white phosphorus in air; it reacts violently with water to form phosphoric acid and is used as a powerful dessicating agent
phosphureted Tweet Definition of phosphureted Like Definition of phosphureted on Facebook
  1. (obsolete),(chemistry) treated, or reacted with phosphorus
photocatalysis Tweet Definition of photocatalysis Like Definition of photocatalysis on Facebook
  1. (chemistry) catalysis by a photocatalyst
photocathode Tweet Definition of photocathode Like Definition of photocathode on Facebook
  1. (physics) A cathode that emits electrons when exposed to light
photochemistry Tweet Definition of photochemistry Like Definition of photochemistry on Facebook
  1. (chemistry) The study of photochemical reactions
photodecomposition Tweet Definition of photodecomposition Like Definition of photodecomposition on Facebook
  1. (chemistry) Any photochemical reaction that results in the decomposition of a substance
photodissociation Tweet Definition of photodissociation Like Definition of photodissociation on Facebook
  1. (chemistry) the dissociation of a molecule following the absorption of a photon
photoisomerization Tweet Definition of photoisomerization Like Definition of photoisomerization on Facebook
  1. (chemistry) The formation of isomers via photoexcitation
photolysis Tweet Definition of photolysis Like Definition of photolysis on Facebook
  1. (chemistry) Any chemical reaction in which a compound is decomposed after absorbing a photon
photooxidation Tweet Definition of photooxidation Like Definition of photooxidation on Facebook
  1. (physics),(chemistry) The loss of an electron from a photoexcited species
  2. (chemistry) The reaction of something with oxygen in the presence of light
photopolymer Tweet Definition of photopolymer Like Definition of photopolymer on Facebook
  1. (chemistry) Any polymer that reacts to light with a physical or chemical change, used especially for teeth fillings
photoreduction Tweet Definition of photoreduction Like Definition of photoreduction on Facebook
  1. (physics),(chemistry) The addition of an electron to a photoexcited species
  2. (chemistry) Any reduction reaction that takes place in the presence of light
phthalein Tweet Definition of phthalein Like Definition of phthalein on Facebook
  1. (chemistry) any of a range of compounds formed by the reaction of phenols with phthalic anhydride
phthalic Tweet Definition of phthalic Like Definition of phthalic on Facebook
  1. (chemistry) of, relating to, or derived from naphthalene or phthalic acid
phthalic acid Tweet Definition of phthalic acid Like Definition of phthalic acid on Facebook
  1. (organic compound) Any of three isomeric aromatic organic dicarboxylic acids, C6H4(COOH)2; especially the ortho- isomer manufactured from naphthalene, used in the synthesis of dyes, perfumes and other compounds.
physical chemistry Tweet Definition of physical chemistry Like Definition of physical chemistry on Facebook
  1. (context, chemistry, physics) The science that uses theories and techniques from physics to study chemical systems.
physicochemical Tweet Definition of physicochemical Like Definition of physicochemical on Facebook
  1. Dependent on the joint action of both physical and chemical processes.
picrate Tweet Definition of picrate Like Definition of picrate on Facebook
  1. (chemistry) any salt or ester of picric acid
picric acid Tweet Definition of picric acid Like Definition of picric acid on Facebook