periodic law 名詞
 週期律
 periodic law
 週期律
 Law n.
 1. In general, a rule of being or of conduct, established by an authority able to enforce its will; a controlling regulation; the mode or order according to which an agent or a power acts.
 Note: ☞ A law may be universal or particular, written or unwritten, published or secret. From the nature of the highest laws a degree of permanency or stability is always implied; but the power which makes a law, or a superior power, may annul or change it.
    These are the statutes and judgments and laws, which the Lord made.   --Lev. xxvi. 46.
    The law of thy God, and the law of the King.   --Ezra vii. 26.
 As if they would confine the Interminable . . .
 Who made our laws to bind us, not himself.   --Milton.
    His mind his kingdom, and his will his law.   --Cowper.
 2. In morals: The will of God as the rule for the disposition and conduct of all responsible beings toward him and toward each other; a rule of living, conformable to righteousness; the rule of action as obligatory on the conscience or moral nature.
 3. The Jewish or Mosaic code, and that part of Scripture where it is written, in distinction from the gospel; hence, also, the Old Testament.  Specifically: the first five books of the bible, called also Torah, Pentatech, or Law of Moses.
    What things soever the law saith, it saith to them who are under the law . . . But now the righteousness of God without the law is manifested, being witnessed by the law and the prophets.   --Rom. iii. 19, 21.
 4. In human government: (a) An organic rule, as a constitution or charter, establishing and defining the conditions of the existence of a state or other organized community. (b) Any edict, decree, order, ordinance, statute, resolution, judicial, decision, usage, etc., or recognized, and enforced, by the controlling authority.
 5. In philosophy and physics: A rule of being, operation, or change, so certain and constant that it is conceived of as imposed by the will of God or by some controlling authority; as, the law of gravitation; the laws of motion; the law heredity; the laws of thought; the laws of cause and effect; law of self-preservation.
 6. In mathematics: The rule according to which anything, as the change of value of a variable, or the value of the terms of a series, proceeds; mode or order of sequence.
 7. In arts, works, games, etc.: The rules of construction, or of procedure, conforming to the conditions of success; a principle, maxim; or usage; as, the laws of poetry, of architecture, of courtesy, or of whist.
 8. Collectively, the whole body of rules relating to one subject, or emanating from one source; -- including usually the writings pertaining to them, and judicial proceedings under them; as, divine law; English law; Roman law; the law of real property; insurance law.
 9. Legal science; jurisprudence; the principles of equity; applied justice.
    Reason is the life of the law; nay, the common law itself is nothing else but reason.   --Coke.
    Law is beneficence acting by rule.   --Burke.
 And sovereign Law, that state's collected will
 O'er thrones and globes elate,
 Sits empress, crowning good, repressing ill.   --Sir W. Jones.
 10. Trial by the laws of the land; judicial remedy; litigation; as, to go law.
    When every case in law is right.   --Shak.
    He found law dear and left it cheap.   --Brougham.
 11. An oath, as in the presence of a court. [Obs.] See Wager of law, under Wager.
 Avogadro's law Chem., a fundamental conception, according to which, under similar conditions of temperature and pressure, all gases and vapors contain in the same volume the same number of ultimate molecules; -- so named after Avogadro, an Italian scientist. Sometimes called Ampère's law.
 Bode's law Astron., an approximative empirical expression of the distances of the planets from the sun, as follows: --
 Mer. Ven. Earth. Mars.  Aste.  Jup.  Sat.  Uran.   Nep.
  4    4     4     4      4      4     4      4      4
  0    3     6    12     24     48    96     192   384
  --   --   --    --     --     --    --     ---   ---
  4    7    10    16     28     52   100     196   388
  5.9  7.3  10    15.2   27.4   52    95.4   192   300
 where each distance (line third) is the sum of 4 and a multiple of 3 by the series 0, 1, 2, 4, 8, etc., the true distances being given in the lower line.
 Boyle's law Physics, an expression of the fact, that when an elastic fluid is subjected to compression, and kept at a constant temperature, the product of the pressure and volume is a constant quantity, i. e., the volume is inversely proportioned to the pressure; -- known also as Mariotte's law, and the law of Boyle and Mariotte.
 Brehon laws. See under Brehon.
 Canon law, the body of ecclesiastical law adopted in the Christian Church, certain portions of which (for example, the law of marriage as existing before the Council of Tent) were brought to America by the English colonists as part of the common law of the land. --Wharton.
 Civil law, a term used by writers to designate Roman law, with modifications thereof which have been made in the different countries into which that law has been introduced. The civil law, instead of the common law, prevails in the State of Louisiana. --Wharton.
 Commercial law. See Law merchant (below).
 Common law. See under Common.
 Criminal law, that branch of jurisprudence which relates to crimes.
 Ecclesiastical law. See under Ecclesiastical.
 Grimm's law Philol., a statement (propounded by the German philologist Jacob Grimm) of certain regular changes which the primitive Indo-European mute consonants, so-called (most plainly seen in Sanskrit and, with some changes, in Greek and Latin), have undergone in the Teutonic languages. Examples: Skr. bhātṛ, L. frater, E. brother, G. bruder; L. tres, E. three, G. drei, Skr. go, E. cow, G. kuh; Skr. dhā to put, Gr. ti-qe`-nai, E. do, OHG, tuon, G. thun.  See also lautverschiebung.
 Kepler's laws Astron., three important laws or expressions of the order of the planetary motions, discovered by John Kepler. They are these: (1) The orbit of a planet with respect to the sun is an ellipse, the sun being in one of the foci. (2) The areas swept over by a vector drawn from the sun to a planet are proportioned to the times of describing them. (3) The squares of the times of revolution of two planets are in the ratio of the cubes of their mean distances.
 Law binding, a plain style of leather binding, used for law books; -- called also law calf.
 Law book, a book containing, or treating of, laws.
 Law calf. See Law binding (above).
 Law day. (a) Formerly, a day of holding court, esp. a court-leet. (b) The day named in a mortgage for the payment of the money to secure which it was given. [U. S.]
 Law French, the dialect of Norman, which was used in judicial proceedings and law books in England from the days of William the Conqueror to the thirty-sixth year of Edward III.
 Law language, the language used in legal writings and forms.
 Law Latin. See under Latin.
 Law lords, peers in the British Parliament who have held high judicial office, or have been noted in the legal profession.
 Law merchant, or Commercial law, a system of rules by which trade and commerce are regulated; -- deduced from the custom of merchants, and regulated by judicial decisions, as also by enactments of legislatures.
 Law of Charles Physics, the law that the volume of a given mass of gas increases or decreases, by a definite fraction of its value for a given rise or fall of temperature; -- sometimes less correctly styled Gay Lussac's law, or Dalton's law.
 Law of nations. See International law, under International.
 Law of nature. (a) A broad generalization expressive of the constant action, or effect, of natural conditions; as, death is a law of nature; self-defense is a law of nature. See Law, 4. (b) A term denoting the standard, or system, of morality deducible from a study of the nature and natural relations of human beings independent of supernatural revelation or of municipal and social usages.
 Law of the land, due process of law; the general law of the land.
 Laws of honor. See under Honor.
 Laws of motion Physics, three laws defined by Sir Isaac Newton: (1) Every body perseveres in its state of rest or of moving uniformly in a straight line, except so far as it is made to change that state by external force. (2) Change of motion is proportional to the impressed force, and takes place in the direction in which the force is impressed. (3) Reaction is always equal and opposite to action, that is to say, the actions of two bodies upon each other are always equal and in opposite directions.
 Marine law, or Maritime law, the law of the sea; a branch of the law merchant relating to the affairs of the sea, such as seamen, ships, shipping, navigation, and the like. --Bouvier.
 Mariotte's law. See Boyle's law (above).
 Martial law.See under Martial.
 Military law, a branch of the general municipal law, consisting of rules ordained for the government of the military force of a state in peace and war, and administered in courts martial. --Kent.  --Warren's Blackstone.
 Moral law, the law of duty as regards what is right and wrong in the sight of God; specifically, the ten commandments given by Moses. See Law, 2.
 Mosaic law, or Ceremonial law. Script. See Law, 3.
 Municipal law, or Positive law, a rule prescribed by the supreme power of a state, declaring some right, enforcing some duty, or prohibiting some act; -- distinguished from international law and constitutional law. See Law, 1.
 Periodic law. Chem. See under Periodic.
 Roman law, the system of principles and laws found in the codes and treatises of the lawmakers and jurists of ancient Rome, and incorporated more or less into the laws of the several European countries and colonies founded by them. See Civil law (above).
 Statute law, the law as stated in statutes or positive enactments of the legislative body.
 Sumptuary law. See under Sumptuary.
 To go to law, to seek a settlement of any matter by bringing it before the courts of law; to sue or prosecute some one.
 To take the law of, or To have the law of, to bring the law to bear upon; as, to take the law of one's neighbor. --Addison.
 Wager of law. See under Wager.
 Syn: -- Justice; equity.
 Usage: -- Law, Statute, Common law, Regulation, Edict, Decree. Law is generic, and, when used with reference to, or in connection with, the other words here considered, denotes whatever is commanded by one who has a right to require obedience. A statute is a particular law drawn out in form, and distinctly enacted and proclaimed. Common law is a rule of action founded on long usage and the decisions of courts of justice. A regulation is a limited and often, temporary law, intended to secure some particular end or object. An edict is a command or law issued by a sovereign, and is peculiar to a despotic government. A decree is a permanent order either of a court or of the executive government. See Justice.
 Pe·ri·od·ic Pe·ri·od·ic·al a.
 1. Of or pertaining to a period or periods, or to division by periods.
    The periodical times of all the satellites.   --Sir J. Herschel.
 2. Performed in a period, or regular revolution; proceeding in a series of successive circuits; as, the periodical motion of the planets round the sun.
 3. Happening, by revolution, at a stated time; returning regularly, after a certain period of time.
    The periodic return of a plant's flowering.   --Henslow.
    To influence opinion through the periodical press.   --Courthope.
 4. Acting, happening, or appearing, at fixed or somewhat variable intervals; recurring; as, periodical epidemics
 5. Rhet. Of or pertaining to a period; constituting a complete sentence.
 Periodic comet Astron., a comet that moves about the sun in an elliptic orbit; a comet that has been seen at two of its approaches to the sun.
 Periodic function Math., a function whose values recur at fixed intervals as the variable uniformly increases. The trigonomertic functions, as  sin(x), tan(x), etc., are periodic functions. Exponential functions are also periodic, having an imaginary period, and the elliptic functions have not only a real but an imaginary period, and are hence called doubly periodic.
 Periodic law Chem., the generalization that the properties of the chemical elements are periodic functions of their atomic weights.  “In other words, if the elements are grouped in the order of their atomic weights, it will be found that nearly the same properties recur periodically throughout the entire series.” The following tabular arrangement of the atomic weights shows the regular recurrence of groups (under I., II., III., IV., etc.), each consisting of members of the same natural family. The gaps in the table indicate the probable existence of unknown elements.
 Periodic table, Periodic table of the elements Chem., A tabular arrangement of the chemical elements, illustrating the periodic law, described above.
 Note: ☞ A modern version of the periodic table can be found at:
        http://periodic.lanl.gov/index.shtml
 Note: ☞ A similar relation had been enunciated in a crude way by Newlands; but the law in its effective form was developed and elaborated by Mendelejeff, whence it is sometimes called Mendelejeff's law.  Important extensions of it were also made by L. Meyer.  By this means Mendelejeff predicted with remarkable accuracy the hypothetical elements ekaboron, ekaluminium, and ekasilicon, afterwards discovered and named respectively scandium, gallium, and germanium.
 -- Periodic star Astron., a variable star whose changes of brightness recur at fixed periods.
 Periodic time of a heavenly body Astron., the time of a complete revolution of the body about the sun, or of a satellite about its primary.
 El·e·ment n.
 1. One of the simplest or essential parts or principles of which anything consists, or upon which the constitution or fundamental powers of anything are based.
 2. One of the ultimate, undecomposable constituents of any kind of matter. Specifically: Chem. A substance which cannot be decomposed into different kinds of matter by any means at present employed; as, the elements of water are oxygen and hydrogen.
 Note: ☞ The elements are naturally classified in several families or groups, as the group of the alkaline elements, the halogen group, and the like. They are roughly divided into two great classes, the metals, as sodium, calcium, etc., which form basic compounds, and the nonmetals or metalloids, as oxygen, sulphur, chlorine, which form acid compounds; but the distinction is only relative, and some, as arsenic, tin, aluminium, etc., form both acid and basic compounds. The essential fact regarding every element is its relative atomic number, which is equal to the number of protons in the nucleus, and also equal to the number of electrons in orbitals around the nucleus when the atom is neutral. When the elements are tabulated in the order of their ascending atomic numbers, the arrangement constitutes the series of the Periodic law of Mendelejeff. See Periodic law, under Periodic. This Periodic law enables us to predict the qualities of unknown elements. The number of elements known in 1890 were about seventy-five, but at that time the gaps in the Periodic law indicated the possibility of many more.  All of the elements up to atomic number 100 have now been observed though some are radioactive and very unstable, and in some cases cannot be accumulated in quantity sufficient to actually see by eye.  The properties predicted by the periodic law wre close to the observed properties in many cases.  Additional unstable elements of atomic number over 100 are observed from time to time, prepared in cyclotrons, particle acclerators, or nuclear reactors, and some of their properties are measurable by careful observation of microscopic quantities, as few as several atoms.  For such unstable elements, the properties are now predicted primarily by calculations based on quantum mechanics. Such theories suggest that there may be an "island" of relative stability of elements of atomic number over 120, but this has yet to be confirmed by experiment.
     Many of the elements with which we are familiar, as hydrogen, carbon, iron, gold, etc., have been recognized, by means of spectrum analysis, in the sun and the fixed stars. The chemical elements are now known not be simple bodies, but only combinations of subatomic particles such as protons, neutrons, and electrons; ahd protons and neutrons are now believed to be themselves combinations of quarks, particles which are not observed singly, but only in combinations.
      In formulas, the elements are designated by abbreviations of their names in Latin or New Latin, given in the table below.  The atomic weights given in the table below are the chemical atomic weights, in some cases being the weighted average of the atomic weights of individual isotopes, each having a different atomic weight.  The atomic weight of the individual isotopes are called the physical atomic weights.  In those few cases where there is only one stable isotope of an element, the chemical and physical atomic weights are the same.  The mass-spectrometric atomic weights are those used for careful mass-spectrometric measurements.  For more details about individual elements, see the element names in the vocabulary
 The Elements
 ------------------------------------------------------------
 Name                   |Sym-|   Atomic  Weight           |
                        |bol |  O=16  |  H=1  | C=12.000
 ------------------------------------------------------------
 Aluminum               | Al |  27.1  |  26.9 |
 Antimony (Stibium)     | Sb | 120    | 119.1 |
 Argon                  | A  |  39.9  |  39.6 |
 Arsenic                | As |  75    |  74.4 |
 Astatine               | At |
 Barium                 | Ba | 137.4  | 136.4 |
 Beryllium              | Be |
 Bismuth                | Bi | 208.5  | 206.9 |
 Boron                  | B  |  11    |  10.9 |
 Bromine                | Br |  79.96 |  79.36|
 Cadmium                | Cd | 112.4  | 111.6 |
 Cesium  (Caesium)      | Cs | 133    | 132   |
 Calcium                | Ca |  40    |  39.7 |
 Carbon                 | C  |  12    |  11.91| 12.000
 Cerium                 | Ce | 140    | 139   |
 Chlorine               | Cl |  35.45 |  35.18|
 Chromium               | Cr |  52.1  |  51.7 |
 Cobalt                 | Co |
 Columbium       (see Beryllium)
 Copper                 | Cu |
   (Cuprum)
 Erbium                 | Er |
 Europium               | Eu |
 Einsteinium            | Es |
 Fermium                | Fe |
 Fluorine               | F  |
 Gadolinium             | Gd |
 Gallium                | Ga |
 Germanium              | Ge |
 Glucinum      (now Beryllium)
 Gold  (Aurum) | Au |
 Helium                 | He |
 Hydrogen               | H  |
 Indium                 | In |
 Iodine                 | I  |
 Iridium                | Ir |
 Iron                   | Fe |
   (Ferrum)
 Krypton                | Kr |
 Lanthanum              | La |
 Lead                   | Pb |
   (Plumbum)
 Lithium                | Li |
 Magnesium              | Mg |
 Manganese              | Mn |
 Mercury                | Hg |
 (Hydrargyrum)
 Molybdenum             | Mo |
 Neodymium              | Nd |
 Neon                   | Ne |
 Nickel                 | Ni |
 Niobium                | Nb |
   (see Columbium)
 Nitrogen               | N  |
 Osmium                 | Os |
 Oxygen                 | O  |
 Palladium              | Pd |
 Phosphorus             | P  |
 Platinum               | Pt |
 Potassium              | K  |
  (Kalium)
 Praseodymium           | Pr |
 Rhodium                | Rh |
 Rubidium               | Rb |
 Ruthenium              | Ru |
 Samarium               | Sa |
 Scandium               | Sc |
 Selenium               | Se |
 Silicon                | Si |
 Silver                 | Ag |
  (Argentum)
 Sodium                 | Na |
    (Natrium)
 Strontium              | Sr |
 Sulphur                | S  |
 Tantalum               | Ta |
 Tellurium              | Te |
 Thallium               | Tl |
 Thorium                | Th |
 Thulium                | Tu |
 Tin                    | Sn |
   (Stannum)
 Titanium               | Ti |
 Tungsten               | W  |
   (Wolframium)
 Uranium                | U  |
 Vanadium               | V  |
 Wolfranium (see Tungsten)
 Xenon                  | X  |
 Ytterbium              | Yb |
 Yttrium                | Y  |
 Zinc                   | Zn |
 Zirconium              | Zr |
 ------------------------------------------------------------
 Note: Several other elements have been announced, as holmium, vesbium, austrium, etc., but their properties, and in some cases their existence, have not yet been definitely established.
 3. One of the ultimate parts which are variously combined in anything; as, letters are the elements of written language; hence, also, a simple portion of that which is complex, as a shaft, lever, wheel, or any simple part in a machine; one of the essential ingredients of any mixture; a constituent part; as, quartz, feldspar, and mica are the elements of granite.
    The simplicity which is so large an element in a noble nature was laughed to scorn.   --Jowett (Thucyd.).
 4. (a) One out of several parts combined in a system of aggregation, when each is of the nature of the whole; as, a single cell is an element of the honeycomb. (b) Anat. One of the smallest natural divisions of the organism, as a blood corpuscle, a muscular fiber.
 5. Biol. One of the simplest essential parts, more commonly called cells, of which animal and vegetable organisms, or their tissues and organs, are composed.
 6. Math. (a) An infinitesimal part of anything of the same nature as the entire magnitude considered; as, in a solid an element may be the infinitesimal portion between any two planes that are separated an indefinitely small distance. In the calculus, element is sometimes used as synonymous with differential. (b) Sometimes a curve, or surface, or volume is considered as described by a moving point, or curve, or surface, the latter being at any instant called an element of the former. (c) One of the terms in an algebraic expression.
 7. One of the necessary data or values upon which a system of calculations depends, or general conclusions are based; as, the elements of a planet's orbit.
 8. pl. The simplest or fundamental principles of any system in philosophy, science, or art; rudiments; as, the elements of geometry, or of music.
 9. pl. Any outline or sketch, regarded as containing the fundamental ideas or features of the thing in question; as, the elements of a plan.
 10. One of the simple substances, as supposed by the ancient philosophers; one of the imaginary principles of matter. (a) The four elements were, air, earth, water, and fire;
 Note: whence it is said, water is the proper element of fishes; air is the element of birds. Hence, the state or sphere natural to anything or suited for its existence.
 Of elements
 The grosser feeds the purer: Earth the Sea;
 Earth and the Sea feed Air; the Air those Fires
 Ethereal.   --Milton.
    Does not our life consist of the four elements?   --Shak.
 And the complexion of the element [i. e.,the sky or air]
 In favor's like the work we have in hand,
 Most bloody, fiery, and most terrible.   --Shak.
    About twelve ounces [of food], with mere element for drink.   --Cheyne.
    They show that they are out of their element.   --T. Baker.
 Esp., the conditions and movements of the air. “The elements be kind to thee.” (b) The elements of the alchemists were salt, sulphur, and mercury.
 11. pl. The whole material composing the world.
    The elements shall melt with fervent heat.   --2 Peter iii. 10.
 12. pl. Eccl. The bread and wine used in the eucharist or Lord's supper.
 Magnetic element, one of the hypothetical elementary portions of which a magnet is regarded as made up.
 periodic law
      n : (chemistry) the principle that chemical properties of the
          elements are periodic functions of their atomic numbers
          [syn: Mendeleev's law]