Part 227

+==============+===============================+==========================+ | NAME AND | OCCURRENCE, PREPARATION AND | COMPOUNDS AND CHIEF USES | |IMPORTANT DATA| PROPERTIES | | +--------------+-------------------------------+--------------------------+ |=Aluminum.= |OCC.--cryolite AlF₃, 3NaF; |Used for cooking utensils,| |Symbol Al. |bauxite, impure Al(OH)₃; in |boat-building, military | |At. wt. 27.1. |feldspars, micas and clay; |accouterments and small | |Valence III. |emery, ruby, sapphire (Al₂O₃). |articles requiring light- | |S. G. 2.7. |PREP.--com’l, by electrolysis |ness and strength; for | |M. P. 658°. |of Al₂O₃, from bauxite, dis- |electric leads. The pow- | |B. P. 1800°. |solved in cryolite, water-power|dered metal is used as a | | |usually furnishing the electri-|body for paint; and its | | |cal energy. |mixture with ferric oxide,| | |PROP.--silver-white, ductile, |called thermite, is used | | |malleable at 120°, tensile |for producing very high | | |strength (wrought) 16 tons per |temperatures (up to | | |sq. in. A better conductor of |3700°C.) for welding | | |electricity, weight for weight,|rails, etc. Many metals | | |than copper. Molten metal not |are reduced from their | | |mobile enough to make castings.|oxides by means of Al, | | |It turns badly in the lathe. |hence its use in casting | | |Acted upon by dil. hydrochloric|steel. Aluminum bronze | | |acid, slowly by sulphuric, but |(10% Al), rolled, has ten-| | |not by nitric or the acids |sile strength of 40 tons | | |occurring in foods. Soluble in |per sq. in. Its sulphate | | |alkaline hydroxides. The tar- |forms alums, e.g., | | |nishing action of moist air |KAl(SO₄)₂, 12H₂O, common | | |soon comes to an end as the |alum. | | |tarnish acts as an adherent | | | |protective coating. | | +--------------+-------------------------------+--------------------------+ |=Antimony.= |OCC.--free, and as stibnite |The metal is a constituent| |Symbol Sb. |(Sb₂S₃). |of the alloy type metal, | |At. wt. 120.2.|PREP.--roasting stibnite gives |Britannia metal and | |Valence III. |Sb₂O₄, which is then reduced by|Babbitt metal (used for | |and V. |heating with carbon. |bearings). Its oxide | |S. G. 6.6. |PROP.--white, brittle, crystal-|(Sb₂O₃) is both basic and | |M. P. 630.7°. |line metal. Its alloys expand |acidic. The trichloride, | |B. P. 1440°. |on solidification, and there- |butter of antimony | | |fore give very sharp castings, |(SbCl₃), is easily hydro- | | |e.g., for type. It does not |lyzed. Tartar emetic | | |tarnish, but may be burned in |(SbOKC₄H₄O₆) is used in | | |air, and unites directly with |medicine and in dyeing. | | |the halogens. | | +--------------+-------------------------------+--------------------------+ |=Argon.= |Present in the air 0.94% by |Forms no compounds, hence | |Symbol A. |volume. To isolate, air is |its name--does no work. Is| |At. wt. 39.86.|freed from CO₂ by soda-lime, |a monatomic gas and is | |Valence nil. |water by P₂O₅, oxygen by red- |identified by its charac-| |Density 39.9 |hot copper, nitrogen by magne- |teristic spectrum seen by | |(oxygen = 32).|sium and calcium. From the |examining the light | |B. P. -186°. |residual mixture argon is ob- |emitted when the gas is | |M. P. -190°. |tained by fractional distilla- |placed in a vacuum tube at| | |tion. |low pressure and sparked. | | | |More soluble in water than| | | |nitrogen, 100 vols. water | | | |dissolving 4 vols. argon | | | |under ordinary conditions.| +--------------+-------------------------------+--------------------------+ |=Arsenic.= |OCC.--free, as arsenical |Used for hardening lead | |Symbol As. |pyrites (FeSAs), as orpiment |for shot. All its com- | |At. wt. 74.96 |(As₂S₃) and as realgar (As₂S₂).|pounds are poisonous. | |Valence III. |PREP.--by heating arsenical |White arsenic (As₂O₃) is | |and V. |pyrites, FeSAs--FeS + As. |partly basic, forming a | |S. G. 5.7. |PROP.--a steel-gray, dully- |chloride and partly acid- | |B. P. 616° |metallic and crystalline ele- |ic, forming arsenites. | |(sublimes). |ment classed as a metalloid |Scheele’s green (CuHAsO₃) | |M. P. about |because intermediate between |is a pigment dangerous in | |800° (under |metals and non-metals. Its |wallpapers. Traces of | |pressure). |vapor has a density correspond-|arsenic are detected by | | |ing to As₄ at 644°, and to As₂ |Marsh’s test in which the | | |at 1700°. It burns in air and |intensely poisonous arsine| | |unites directly with the halo- |(AsH₃) is formed. | | |gens, sulphur and with many | | | |metals. | | +--------------+-------------------------------+--------------------------+ |=Barium.= |OCC.--as barytes or heavy-spar |The peroxide (BaO₂) is | |Symbol Ba. |(BaSO₄), and as witherite |used in the manufacture of| |At. wt. |(BaCO₃). |oxygen and of hydrogen | |137.37. |PREP.--by electrolysis of the |peroxide. The nitrate and | |Valence II. |fused chloride. |chlorate in pyrotechny to | |S. G. 3.8. |PROP.--a silver-white, lus- |give green fires. The sul-| |M. P. 850°. |trous, malleable metal harder |phate as the body for a | | |than lead. Like calcium, it |permanent white paint and | | |acts slowly on water to give |for filling glazed paper. | | |barium hydroxide and hydrogen. |All soluble compounds are | | |The vapors of its compounds |poisonous. | | |impart a green color to the | | | |Bunsen flame. | | +--------------+-------------------------------+--------------------------+ |=Bismuth.= |OCC.--free and as trioxide |Used for making fusible | |Symbol Bi. |(Bi₂O₃) and trisulphide |alloys, e.g. Wood’s metal,| |At. wt. 208.0 |(Bi₂S₃). |M. P. 60.5°, which are | |Valence III. |PREP.--the ore is roasted and |used in plugs of fire | |(and V.). |then heated with charcoal and |sprinklers and boiler | |S. G. 9.8. |metallic iron (to remove traces|safety valves, and for | |M. P. 270.9°. |of sulphur.) |taking casts. The oxy- | |B. P. 1420°. |PROP.--an exceedingly brittle, |nitrate is used in med- | | |crystalline shining metal, |icine and as a cosmetic. | | |white with a tinge of pink. | | | |Bismuth expands on solidifica- | | | |tion. It does not tarnish, but | | | |can be burnt in air. Dissolves | | | |in oxygen acids. | | +--------------+-------------------------------+--------------------------+ |=Boron.= |OCC.--as boric acid (H₃BO₃), |The compounds are analo- | |Symbol B. |borax (Na₂B₄O₇, 10H₂O), coleman-|gous to those of silicon.| |At. wt. 11.0. |ite (Ca₂B₆O₁₁, 5H₂O). |Borax is used as a flux, | |Valence III. |PREP.--amorphous boron by re- |and, in solution, as a | |S. G. |ducing B₂O₃ with Mg. Impure |mild alkali on account of | |(amorph.) 2.4;|cryst. boron by reducing B₂O₂ |its hydrolysis. Boric acid| |(cryst.) 2.5. |with excess of Al. |is used as a weak anti- | |B. P. 3500° |PROP.--amorphous boron is a |septic and preservative. | |(sublimes). |greenish-black powder that | | | |burns in air at 700°, forming | | | |B₂O₃ and also BN. It is oxi- | | | |dized, by hot conc. sulphuric | | | |or nitric acids, to boric acid.| | +--------------+-------------------------------+--------------------------+ |=Bromine.= |OCC.--in seawater as alkali |Potassium bromide is used | |Symbol Br. |bromide, and in the upper |in medicine, silver | |At. wt. 79.22 |layers of salt deposits as |bromide in photography. | |Valence I. |sodium and magnesium bromide. |Bromine is used in course | |S. G. 3.1 |PREP.--by treatment of the |of the preparation of | |B. P. 59°. |brines with sulphuric acid and |organic dyes. | |M. P. -7.3°. |manganese dioxide, or else with| | | |chlorine. | | | |PROP.--a dark red liquid, | | | |smelling like chlorine, whose | | | |vapor irritates eyes, throat | | | |and nose. Dissolves in thirty | | | |parts of water (bromine water).| | | |Combines directly with most | | | |other elements, but less vigor-| | | |ously than chlorine. | | +--------------+-------------------------------+--------------------------+ |=Cadmium.= |OCC.--in association with the |All the compounds are | |Symbol Cd. |zinc ores, as carbonate and |poisonous, and little | |At. wt. |sulphide. |ionized. The sulphide | |112.40. |PREP.--in the distillation of |(CdS) is the basis of | |Valence II. |impure zinc, the cadmium comes |“cadmium yellow.” The | |S. G. 8.6. |over in the first portions. |iodide is used in medi- | |M. P. 320.9°. |PROP.--a silver-white metal, |cine. | |B. P. 766°. |more ductile and malleable than| | | |zinc. It burns in air, and is | | | |attacked by dilute acids. | | +--------------+-------------------------------+--------------------------+ |=Caesium.= |OCC.--in certain micas, and in |The compounds are charac- | |Symbol Cs. |the ashes of certain plants. |terized by giving, es- | |At. wt. |PREP.--by heating the hydroxide|pecially, two bright lines| |132.81. |(CsOH) with magnesium. |in the blue of the | |Valence I. |PROP.--a white, silvery metal |spectrum (caesius sky- | |S. G. 1.9. |resembling potassium. It is one|blue). | |M. P. 26.3°. |of the most active of metals, | | |B. P. 670°. |and decomposes water violently.| | +--------------+-------------------------------+--------------------------+ |=Calcium.= |OCC.--as carbonate (Iceland |Calcium oxide (quicklime) | |Symbol Ca. |spar, calcite, aragonite, |is used for mortar and to | |At. wt. 40.07.|marble, chalk, limestone), |remove hair from hides. | |Valence II. |sulphate (gypsum), phosphate |The hydroxide [Ca(OH)₂] | |S. G. 1.55. |(apatite), fluoride (fluor |mixed with sand forms | |M. P. 803°. |spar), and as complex silicates|mortar; its solution is | | |in great variety (feldspars, |limewater. Plaster of | | |pyroxenes, amphiboles, etc.). |paris, a less hydrated | | |PREP.--by electrolysis of the |sulphate, takes up water | | |fused chloride. |on setting to form CaSO₄, | | |PROP.--a white crystalline |2H₂O. The phosphates are | | |metal, harder than lead, that |fertilizers. Bleaching | | |can be cut, drawn, rolled and |powder is CaClOCl and | | |turned. It attacks water, and |calcium carbide is CaC₂. | | |burns in the air at a red heat |Common glass contains | | |forming the oxide (CaO) and the|silicates of calcium and | | |nitride (Ca₃N₂). It unites with|sodium. | | |hydrogen to CaH₂, whose action | | | |on water is a source of | | | |hydrogen for balloons. | | +--------------+-------------------------------+--------------------------+ |=Carbon.= |OCC.--as diamond and graphite, |The carbon compounds form | |Symbol C. |in the free state; in combina- |the subject of “Organic | |At. wt. |tion with hydrogen as petro- |Chemistry.” Carbon dioxide| |12.005. |leum, with oxygen as carbon di-|results from the burning | |Valence IV. |oxide in the air, with these |of coal, coke, wood, oil | |S. G. diamond |and other elements as coal, and|or illuminating gas; from | |3.5: graphite |in plant and animal tissues; |fermentation and decay, | |2.3: amorphous|and as many carbonates. |which are slow burnings; | |1.9 |PREP.--by dry distillation of |and is exhaled in the | |M. P.--not |wood or coal, yielding charcoal|breath. Carbon monoxide, | |realized; |and coke respectively. |arising from recently- | |estimated at |PROP.--diamond is crystalline |stoked fires, is an ex- | |4400°. |and the hardest of minerals, |ceedingly poisonous gas. | | |the dark-colored “bort” being | | | |used for cutting and grinding. | | | |Graphite has a black metallic | | | |luster, is crystalline and may | | | |be scratched by the finger- | | | |nail. Charcoal is amorphous, | | | |and possesses the power of ab- | | | |sorbing gases and also coloring| | | |matters. All three forms burn | | | |in oxygen to produce carbon | | | |dioxide. | | +--------------+-------------------------------+--------------------------+ |=Cerium.= |OCC.--as silicate in cerite, |Welsbach incandescent gas | |Symbol Ce. |along with Nd, Pr and La; also |mantles contain one per | |At. wt. |in monazite sand. |cent of cerium dioxide, | |140.25. |PREP.--by electrolysis of the |CeO₂. | |Valence III., |fused chloride. | | |IV. (and VI.).|PROP.--a metal with the color | | |S. G. 6.8; |and luster of iron, like tin in| | |M. P. 623°. |hardness, and very ductile and | | | |malleable. Burns in air more | | | |easily and brightly than | | | |magnesium. | | +--------------+-------------------------------+--------------------------+ |=Chlorine.= |OCC.--in seawater as chlorides |The gas is used in ex- | |Symbol Cl. |of the alkalis and alkaline |tracting gold and in pre- | |At. wt. 35.46.|earths, and as like compounds |paring bleaching and dis- | |Valence I. |in salt deposits. |infecting agents. In pre- | |(and VII.). |PREP.--by electrolysis of |sence of water it bleaches| |S. G. (liquid)|alkali chloride, fused or in |many coloring matters. | |1.3. |solution; or by the action of |Forms chlorides (as NaCl, | |M. P. -101°. |manganese dioxide on hydro- |HCl, CaCl₂), hypochlorides| |B. P. -33.6°. |chloric acid. |[as solution of Ca(OCl)₂],| |C. T. +146°. |PROP.--a greenish-yellow gas of|chlorates (as KClO₃, used | | |characteristic odor, with a |for matches and in pyro- | | |violent action on the respira- |techny), and perchlorates | | |tory tract. Unites directly |(as KClO₄). | | |with all elements save oxygen, | | | |nitrogen and the argon family. | | | |Displaces bromine and iodine | | | |from bromides and iodides, and | | | |substitutes hydrogen in organic| | | |compounds. | | +--------------+-------------------------------+--------------------------+ |=Chromium.= |OCC.--as chromite [Fe(CrO₂)₂]. |The alloy ferrochromium is| |Symbol Cr. |PREP.--by reducing Cr₂O₃ with |used in steel-making. | |At. wt. 52.0. |aluminum filings. |Chrome green, the pigment,| |Valence II., |PROP.--a steel-gray, lustrous, |is Cr₂O₃. Chrome yellow is| |III. and VI. |brittle and very hard metal. At|PbCrO₄. Bichromates (as | |S. G. 6.6. |high temperatures it burns in |K₂Cr₂O₇) are used in | |M. P. 1515°. |air to green Cr₂O₃. It is |photo-processes, tanning | |B. P. 2200°. |attacked by dilute sulphuric or|and dyeing and as oxi- | | |hydrochloric acid, but not by |dizing agents, e.g., in | | |nitric acid. |batteries. | +--------------+-------------------------------+--------------------------+ |=Cobalt.= |OCC.--as smaltite (CoAs₂) and |Its intensely blue sili- | |Symbol Co. |cobaltite (CoAsS). |cates are used in coloring| |At. wt. 58.97.|PREP.--by igniting the oxide in|porcelain and constitute | |Valence II. |hydrogen. |the pigment smalt. | |and III. |PROP.--a white, magnetic, mal- | | |S. G. 8.6. |leable metal, less tenacious | | |M. P. 1490°. |than iron. By exposure it turns| | | |pinkish. It is less active | | | |chemically than iron. | | +--------------+-------------------------------+--------------------------+ |=Columbium= |OCC.--in the mineral columbite.|The hydride (CbH) burns in| |(Niobium) |PREP.--by reduction of CbO₂ by |air. The compounds occur | |Symbol Cb. |paraffin. |with those of tantalum, | |At. wt. 93.5. |PROP.--a light-gray, malleable |which they closely | |Valence I., |and ductile metal, as hard as |resemble. | |II., IV. and |wrought iron, which is not | | |V. |affected by acids, even by aqua| | |S. G. 12.7. |regia. | | |M. P. 1950°. | | | +--------------+-------------------------------+--------------------------+ |=Copper.= |OCC.--free, as cuprite (Cu₂O), |The metal is used for | |Symbol Cu. |copper glance (Cu₂S), chalcopy-|coins, electroplating, | |At. wt. 63.57.|rite (Cu₂S, Fe₂S₃), malachite |electric leads, roofing, | |Valence I. and|[CuCO₃, Cu(OH)₃]. |cooking vessels and for | |II. |PREP.--after removal of iron |making alloys, such as | |S. G. 8.9. |and sulphur, the oxide is re- |brass, bell and gun | |M. P. 1083°. |duced by heating with carbon. |metals, German silver and | |B. P. 2310°. |It is refined electrolytically.|the bronzes. The soluble | | |PROP.--a red, lustrous, very |compounds are poisonous, | | |ductile and malleable metal of |and are therefore used as | | |tensile strength fourteen tons |germicides in agriculture.| | |per square inch, second only to|Blue vitriol is CuSO₄ | | |silver in electrical conductiv-|5H₂O; the basic acetate is| | |ity. In ordinary air it gradu- |verdigris. | | |ally becomes coated with basic | | | |carbonate. In absence of air, | | | |nitric acid alone among the | | | |dilute acids attacks it, but in| | | |presence of air even the acids | | | |found in foodstuffs can dis- | | | |solve it. | | +--------------+-------------------------------+--------------------------+ |=Dysprosium.= |OCC.--in monazite, gadolinite, |The salts are green or | |Symbol Dy. |etc. |yellow in color and show | |At. wt. 162.5.|PREP.--not yet isolated. |characteristic absorption | |Valence III. |PROP.--the oxide dysprosia, |bands. | | |along with three other rare | | | |earths, constitutes erbia. | | +--------------+-------------------------------+--------------------------+ |=Erbium.= |OCC.--same as for dysprosium. |The salts are rose- | |Symbol Er. |PREP.--not yet isolated pure. |colored, and show charac- | |At. wt. 167.7.|PROP.--crude erbia has been |teristic absorption | |Valence III. |separated into erbia, holmia, |spectra. | |S. G. 4.8. |thulia, and dysprosia. | | +--------------+-------------------------------+--------------------------+ |=Europium.= |OCC.--in monazite and other |The salts are pinkish and | |Symbol Eu. |rare minerals. |show a faint absorption | |At. wt. 152.0.|PREP.--not yet isolated. |spectrum. | |Valence III. |PROP.--this element so closely | | | |resembles samarium that the | | | |analytical separation of the | | | |two is difficult. | | +--------------+-------------------------------+--------------------------+ |=Fluorine.= |OCC.--as cryolite (AlF₃, 3NaF),|Hydrogen fluoride is used | |Symbol F. |fluor spar (CaF₂) and very |for etching glass and in | |At. wt. 19.0. |widely elsewhere in small quan-|silicate analysis. Silver | |Valence I. |tities. |fluoride is soluble and | |S. G. (liquid)|PREP.--by electrolysis of dry |calcium fluoride insolu- | |1.11 at -187°.|hydrogen fluoride at -23°. |ble, in contrast with the | |M. P. -223°. |PROP.--a pale yellowish-green |other halides of these | |B. P. -187°. |gas that unites with every |metals. | | |element excepting oxygen and | | | |the argon family. It rapidly | | | |displaces oxygen from water or | | | |chlorine from hydrogen | | | |chloride. | | +--------------+-------------------------------+--------------------------+ |=Gadolinium.= |OCC.--in gadolinite and |The salts are colorless | |Symbol Gd. |samarskite. |and show no absorption | |At. wt. 157.3.|PREP.--not yet isolated. |bands. | |Valence III. |PROP.--This element closely | | | |resembles terbium in its | | | |compounds. | | +--------------+-------------------------------+--------------------------+ |=Gallium.= |OCC.--in zinc blende and in |It forms two chlorides | |Symbol Ga. |bauxite. |(GaCl₃ and GaCl₂) which | |At. wt. 69.9. |PREP.--by electrolysis of a |yield spark spectra very | |Valence III. |suitable solution of its salts.|characteristic of gallium.| |S. G. 5.9. |PROP.--a bluish-white, tough | | |M. P. 30.1°. |metal that may be cut with a | | | |knife. Like aluminum, it is | | | |soluble in hydrochloric acid | | | |and in caustic alkali, but not | | | |in nitric acid. | | +--------------+-------------------------------+--------------------------+ |=Germanium.= |OCC.--in the rare mineral |The close relation of this| |Symbol Ge. |argyrodite. |element to carbon and | |At. wt. 72.5. |PREP.--by the reduction of the |silicon is shown in the | |Valence II. |dioxide (GeO₂) by carbon. |compound germanium chloro-| |and IV. |PROP.--a grayish-white, brit- |form (GeHCl₃). | |S. G. 5.5. |tle, lustrous metal, insoluble | | |M. P. 958°. |in hydrochloric acid. It com- | | | |bines directly with the halo- | | | |gens. | | +--------------+-------------------------------+--------------------------+ |=Glucinum= (or|OCC.--in beryl [Al₂Gl₂(SiO₃)₆].|Its hydroxide [Gl(OH)₂] is| |Beryllium). |PREP.--by electrolysis of the |feebly acidic as well as | |Symbol Gl. |fused double fluoride, GlF₂, |basic, thus resembling the| |At. wt. 9.1. |2KF. |hydroxide of zinc. Emerald| |Valence II. |PROP.--a hard, white metal that|is beryl colored green by | |S. G. 1.7. |tarnishes when heated in air, |chromium. | |M. P. below |and is soluble in dilute acids | | |960°. |when powdered. | | +--------------+-------------------------------+--------------------------+ |=Gold.= |OCC.--chiefly free, but also as|Pure gold is called 24- | |Symbol Au. |telluride; many specimens of |carat gold. American, | |At. wt. 197.2.|iron are auriferous. |French and German gold | |Valence I. and|PREP.--from gold-bearing sands |coins are 21.6 carat, | |III. |by washing away the lighter |while British sovereigns | |S. G. 19.32. |material, and dissolving the |are 22 carat, the balance | |M. P. 1062.4°.|gold from the residue by mer- |in all these cases being | | |cury, which is subsequently |copper. Jewelry is made in| | |separated from the gold by |18, 14, 9, etc., carat | | |distillation. Quartz ores are |gold, the addition of | | |pulverized in stamping mills, |copper increasing the | | |and the powder is then carried |hardness and rigidity. | | |by water over amalgamated |Sodium chloraurate | | |copper plates on which the gold|(NaAuCl₄) is used for | | |collects. |“toning” in photography, | | |PROP.--a soft, bright-yellow |while potassium auri- | | |metal, easily scratched by the |cyanide [KAu(CN)₄] is used| | |knife, an excellent conductor |in electro-gilding. | | |of heat and of electricity. The| | | |most ductile and the most mal- | | | |leable of all the metals. | | | |Chemically, gold is rather in- | | | |ert, and is not attacked by the| | | |oxygen of the air, by hydrogen | | | |sulphide, nor, indeed, by any | | | |single one of the common acids.| | | |It is attacked by fused alka- | | | |lis, yielding aurates, and by | | | |aqua regia, yielding chlorauric| | | |acid (HAuCl₄). | | +--------------+-------------------------------+--------------------------+ |=Helium.= |OCC.--in air to the extent of |It is one of the decompo- | |Symbol He. |one to two volumes per million;|sition products of certain| |At. wt. 4.00. |also occluded in certain |other (radio-active) | |Valence 0. |minerals. |elements. | |S. G. (liquid |PREP.--neon and helium are | | |at B.P.) |boiled off crude argon, and the| | |0.122. |neon solidified by cooling. | | |M. P. -272°. |PROP.--the lightest gas after | | |B. P. -268.7°.|hydrogen, transparent, odorless| | | |and colorless, very inert, | | | |forming no compounds with other| | | |elements. | | +--------------+-------------------------------+--------------------------+ |=Holmium.= |... |... | |Symbol Ho. | | | |At. wt. 163.5.| | | |Valence III. | | | +--------------+-------------------------------+--------------------------+ |=Hydrogen.= |OCC.--in air to the extent of |Its two oxides are water | |Symbol H. |one volume per 20,000 volumes |(H₂O) and hydrogen per- | |At. wt. 1.008.|air; combined, in water (11.19%|oxide (H₂O₂), the latter | |Valence I. |by weight) natural gas, petro- |of which is used in solu- | |S. G. (liquid |leum and all animal and vege- |tion as a bleaching agent.| |at B.P.) 0.07.|table bodies. |Every acid contains hydro-| |M. P. -259°. |PREP.--by treating zinc with |gen as an essential con- | |B. P. -252.5°.|hydrochloric or sulphuric acid;|stituent. Its compounds | | |by electrolysis of water. |with carbon and other | | |PROP.--the lightest gas, trans-|elements number over | | |parent, odorless and colorless,|100,000. Hydrogen gas is | | |soluble in water (2 volumes in |used for the oxyhydrogen | | |100 volumes water under every- |flame and for filling | | |day conditions), in platinum, |balloons. | | |in palladium (502 volumes in 1 | | | |of Pd). Burns in air and in | | | |chlorine, and unites with many | | | |of the other elements. | | +--------------+-------------------------------+--------------------------+ |=Indium.= |OCC.--in zinc blende (ZnS). |Its compounds color the | |Symbol In. |PREP.--electrolytically from |nonluminous gas flame blue| |At. wt. 114.8.|solutions of its salts. |and show a characteristic | |Valence III. |PROP.--a white metal, malleable|blue line in the spectrum.| |and I. |and softer than lead. | | |S. G. 7.3. | | | |M. P. 155°. | | | +--------------+-------------------------------+--------------------------+ |=Iodine.= |OCC.--in the ocean, in certain |Its tincture is used in | |Symbol I. |seaweeds, and in Chili salt- |medicine as a counterirri-| |At. wt. |peter, always in the combined |tant. Potassium iodide | |126.92. |state. |(KI) and iodoform (CHI₃) | |Valence I., V.|PREP.--from iodides by dis- |likewise find application | |and VII. |placement of their iodine by |in medicine. The alkyl | |S. G. 4.94. |chlorine. |iodides (e.g., C₂H₅I) are | |M. P. 114°. |PROP.--a dark gray, brittle |much used in synthetic | |B. P. 184°. |solid with a metallic luster. |organic chemistry. | | |Its vapor is violet, as are its| | | |solutions in chloroform and in | | | |carbon bisulphide. It requires | | | |over 5,000 parts of water for | | | |its solution. Combines directly| | | |with many elements, but is much| | | |less active than chlorine and | | | |bromine. | | +--------------+-------------------------------+--------------------------+ |=Iridium.= |OCC.--along with platinum. |It is used for pointing | |Symbol Ir. |PREP.--by a complex series of |gold pens. Its alloy with | |At. wt. 193.1.|operations from platinum ores. |nine parts of platinum is | |Valence III. |PROP.--a white metal, brittle |used for standard meter | |and IV. |when cold, and very hard. It is|bars on account of its | |S. G. 22.4. |attacked by fused alkalies, but|inalterability. | |M. P. 2300°. |not by aqua regia. | | +--------------+-------------------------------+--------------------------+ |=Iron.= |OCC.--as magnetic oxide |The metal is used as a | |Symbol Fe. |(Fe₂O₄), hematite (Fe₂O₃), |structural material, for | |At. wt. 55.85.|limonite (2Fe₂O₃, 3H₂O), |rails, machinery, tools, | |Valence II. |siderite (Fe₂CO₃), which are im-|etc. Jeweler’s rouge and | |and III. |portant ores; iron pyrites |Venetian red consist of | |S. G. 7.86; |(FeS₂); in rocks as complex |the oxide (Fe₂O₃). Rust is| |pig 7.03 to |silicates, and in plants and |chiefly the hydrated oxide| |7.73. |animals. |(FeO, OH). Hammer scale | |M. P. 1515°. |PREP.--pig iron is prepared in |and loadstone have the | |B. P. 2450°. |the blast furnace by reduction |composition Fe₃O₄. Ferric | |wrought 1100°-|of the ore by means of carbon |chloride (FeCl₃), ferrous | |1500°. |monoxide in presence of a |iodide (FeI₂) and other | |steel 1375°. |suitable flux. From pig iron, |iron compounds are used in| |gray pig |wrought iron is obtained by |medicine. Green vitriol | |1275°. |puddling, and steel by the |(FeSO₄, 7H₂O) is used in | |white pig |Bessemer, Siemens-Martin or |making ink, and in dyeing.| |1075°. |other process. |Potassium ferrocyanide | | |PROP.--a white, malleable, |[K₄Fe(CN)₆] is used for | | |ductile, magnetic metal, un- |making Prussian blue, | | |changed in dry air or air-free |potassium cyanide, etc. | | |water, but rusting in moist | | | |air. Easily attacked by dilute | | | |acids, but not by fused alka- | | | |lies. Cast iron contains 2 to | | | |5% of carbon and other impuri- | | | |ties, and is hard and brittle. | | | |Wrought iron contains less than| | | |0.2% of carbon, and is softer | | | |and tougher, with a tensile | | | |strength of 22 to 25 tons per | | | |square inch. Steel contains | | | |from 0.2 to 1.5% of carbon, is | | | |permanently magnetic, may be | | | |tempered, and possesses tensile| | | |strength up to 100 tons | | | |per square inch. | | +--------------+-------------------------------+--------------------------+ |=Krypton.= |OCC.--in minute quantity in the|It forms no compounds, and| |Symbol Kr. |air. |is identified by its | |At. wt. 82.92.|PREP.--from crude argon by |characteristic spectrum. | |Valence 0. |fractional distillation. | | |S. G. (Liquid |PROP.--an inert, colorless, | | |at B. P.) 2.2.|odorless gas, resembling, but | | |M. P. -169°. |denser than, argon. | | |B. P. -152°. | | | +--------------+-------------------------------+--------------------------+ |=Lanthanum.= |OCC.--as lanthanite [La₂(CO₃)₃,|When heated in air it | |Symbol La. |8H₂O]. |forms oxide (La₂O₃) and | |At. wt. 139.0.|PREP.--by electrolysis of fused|nitride (LaN). | |Valence III. |LaCl₃. | | |and V. |PROP.--an iron-gray metal | | |S. G. 6.15. |tarnishing in air to steel- | | |M. P. 810°. |blue; malleable and ductile. | | | |Attacked slowly even by cold | | | |water. | | +--------------+-------------------------------+--------------------------+ |=Lead.= |OCC.--as galena (PbS), and in |The metal is used for | |Symbol Pb. |silver ores. |water pipes, roofs and | |At. wt. |PREP.--by calcination of par- |gutters and storage bat- | |207.20. |tially roasted galena. Purifi- |teries. For shot it is | |Valence II., |cation is effected by Parkes |alloyed with 0.4% of | |IV. |process. |arsenic. Typemetal con- | |S. G. 11.4. |PROP.--a soft, gray metal, |tains 20% of antimony. | |M. P. 327.2°. |malleable, but of low tensile |Babbitt metal, for bear- | |B. P. 1525°. |strength. In presence of air, |ings, contains over 70% of| | |water acts on lead to produce |lead. Solder and pewter | | |the hydroxide, which being |are alloys of lead and | | |slightly soluble, may cause |tin. The basic carbonate | | |lead poisoning, if present in |[Pb(OH)₂, 2PbCO₃], “white | | |water supplies. When heated in |lead,” is the basis of | | |air it is oxidized to litharge |most oil paints. | | |(PbO), and, under suitable con-| | | |ditions, to minimum (Pb₃O₄) | | +--------------+-------------------------------+--------------------------+ |=Lithium.= |OCC.--as a mixed fluoride with |The carbonate [Li₂(CO₃)] | |Symbol Li. |aluminium in amblygonite. |is used in medicine as a | |At. wt. 6.94. |PREP.--by electrolysis of the |solvent for uric acid, | |Valence I. |fused chloride. |lithium urate being solu- | |S. G. 0.53. |PROP.--a silver-white metal, |ble. The lithium salts | |M. P. 186°. |softer than lead, that tar- |give a carmine flame | |B. P. above |nishes quickly in air, and is |coloration. | |1400°. |easily acted upon by water. | | | |When heated, it unites vigor- | | | |ously with nitrogen. | | +--------------+-------------------------------+--------------------------+ |=Lutecium.= |OCC.--in euxenite. |Its compounds resemble | |Symbol Lu. |PREP.--it has not been |those of ytterbium. | |At. wt. 175.0.|isolated. | | +--------------+-------------------------------+--------------------------+ |=Magnesium.= |OCC.--as magnesite (MgCO₂), |The sulphate (MgSO₄, 7H₂O)| |Symbol Mg. |dolomite (MgCO₃, CaCO₃), |is known as epsom salts | |At. wt. 24.32.|carnallite (MgCl₂, KCl, 6H₂O) |and is used in medicine, | |Valence II. |and in very many complex sili- |as are the oxide (magne- | |S. G. 1.75. |cates. |sia), the carbonates and | |M. P. 650°. |PREP.--by electrolysis of |citrate. Magnalium is a | |B. P. 1120°. |dried, fused carnallite. |light, hard alloy with | | |PROP.--a silver-white metal, |aluminum. | | |ductile when hot. It tarnishes | | | |in air, and acts slowly upon | | | |water, rapidly on steam. Burns | | | |in air to the oxide MgO, | | | |emitting a very bright light | | | |used in photography. It unites | | | |directly with nitrogen. | | +--------------+-------------------------------+--------------------------+ |=Manganese.= |OCC.--as pyrolusite (MnO₂), |Ferromanganese and | |Symbol Mn. |beaunite (Mn₂O₃), hausmannite |spiegeleisen are alloys | |At. wt. 54.93.|(Mn₃O₄) and manganese spar |with iron, used in steel | |Valence II., |(MnCO₃). |making. With copper it | |III., IV., VI.|PREP.--by heating Mn₃O₄ with |forms the hard, tough | |and VII. |aluminum filings. |manganese bronzes, with | |S. G. 7.3. |PROP.--a steel-gray, hard, |tensile strength up to 30 | |M. P. 1120°. |brittle metal with a pinkish |tons per square inch. Im- | |B. P. 1900°. |tinge. It rusts in moist air |pure sodium permanganate | | |and is attacked by dilute |(NaMnO₄) is used in disin-| | |acids. |ecting as Condy’s fluid. | +--------------+-------------------------------+--------------------------+ |=Mercury.= |OCC.--free and as cinnabar |It is used for filling | |Symbol Hg. |(HgS). |thermometers and baro- | |At. wt. 200.6.|PREP.--by roasting cinnabar HgS|meters. Its alloys are | |Valence I. and|+ O₂--Hg + SO₂. |called amalgams, some of | |II. |PROP.--a silver-white, mobile |which are used in dentist-| |S. G. 13.6. |liquid with a vapor pressure at|ry. Calomel (HgCl) is | |M. P. -39.5°. |0° of 0.0002 mm. It tarnishes |administered internally in| |B. P. 356.95°.|but slowly in air and is |medicine; corrosive sub- | | |attacked only by dilute nitric |limate (HgCl₂) forms a | | |among the dilute acids. The |solution with very power- | | |vapor is monatomic. |ful germicidal properties.| +--------------+-------------------------------+--------------------------+ |=Molybdenum.= |OCC.--as molybdenite (MoS₂) and|The ferromolybdenum alloys| |Symbol Mo. |wulfenite (PbMoO₄). |are used in the manufac- | |At. wt. 96.0. |PREP.--by reducing the oxides |ture of special steels. | |Valence III., |with aluminum powder. | | |IV., V. and |PROP.--a white metal, as malle-| | |VI. |able as iron, that will not | | |S. G. 10.0. |scratch glass. Insoluble in | | |M. P. 2450°. |hydrochloric or dilute sulphur-| | | |ic acid. | | +--------------+-------------------------------+--------------------------+ |=Neodymium.= |OCC.--with cerium and |The salts are rose-violet | |Symbol Nd. |lanthanum. |in color, and their solu- | |At. wt. 144.3.|PREP.--by electrolysis of the |tions show characteristic | |Valence III. |fused chloride. |absorption spectra. | |and IV. |PROP.--a yellowish metal, tar- | | |S. G. 7.0. |nishing in air. | | |M. P. 840°. | | | +--------------+-------------------------------+--------------------------+ |=Neon.= |OCC.--in minute quantity in the|It forms no compounds, and| |Symbol Ne. |atmosphere. |is recognized by its | |At. wt. 20.2. |PREP.--neon and helium are |characteristic spectrum. | |Valence 0. |boiled out of crude argon, and | | |B. P. ca. |the neon separated from helium | | |-243°. |by cooling with liquid hydro- | | | |gen. | | | |PROP.--a colorless, trans- | | | |parent, odorless, inert gas, | | | |resembling argon. | | +--------------+-------------------------------+--------------------------+ |=Nickel.= |OCC.--as nicollite (NiAs) and |The metal furnishes a pro-| |Symbol Ni. |nickel glance (NiAsS). |tective coating when | |At. wt. 58.68.|PREP.--by igniting the oxalate |plated on iron. German | |Valence II. |in hydrogen. |silver is an alloy of | |and III. |PROP.--a white, very hard, |nickel, copper and zinc. | |S. G. 8.8. |lustrous metal, malleable, |Nickel steel is used for | |M. P. ca. |ductile and tenacious. It rusts|armor plates. Manganin, | |1452°. |but slowly in air, and is |containing nickel, copper | |B. P. ca. |attacked easily by only nitric |and manganese, is used for| |2600°. |acid. |electrical resistances. | +--------------+-------------------------------+--------------------------+ |=Nitrogen.= |OCC.--free nitrogen forms about|Nitrous oxide (N₂O), or | |Symbol N. |four-fifths of air by volume. |laughing gas, is used by | |At. wt. 14.01.|As Bengal saltpeter (KNO₃), |dentists. Nitric acid | |Valence III. |Chili saltpeter (NaNO₃); and as|(HNO₃) has many applica- | |and V. |an essential constituent of |tions in technical | |S. G. (liquid |vegetable and animal proto- |chemistry. Ammonia (NH₃) | |at B. P.) |plasm. |is a very soluble gas. | |0.81. |PREP.--by heating ammonium |Ammonium sulphate | |M. P. -214°. |nitrite, by oxidation of |[(NH₄)₂SO₄] and Chili | |B. P. -194°. |ammonia, etc. |saltpeter are used as | | |PROP.--a colorless, odorless, |nitrogenous manures. | | |transparent gas, rather in- |Nitrogen is a constituent | | |active chemically. At ordinary |of the aniline dyes, the | | |temperature and pressure, 100 |proteins and many other | | |volumes of water dissolve 1.5 |important classes of | | |volumes of nitrogen. It unites |organic substances. | | |directly with strongly heated | | | |boron, lithium, calcium and | | | |magnesium. | | +--------------+-------------------------------+--------------------------+ |=Osmium.= |OCC.--along with platinum. |Its alloy with iridium is | |Symbol Os. |PREP.--by reducing OsO₄. |used in tipping gold pens.| |At. wt. 190.9.|PROP.--a gray metal, harder |Osmium tetroxide (OsO₄) is| |Valence II., |than glass, the heaviest of |used as a microscopic | |III., IV., VI.|known bodies. |stain for fat. | |and VIII. | | | |S. G. 22.477. | | | |M. P. 2500°. | | | +--------------+-------------------------------+--------------------------+ |=Oxygen.= |OCC.--free oxygen forms about |The gas is sold compressed| |Symbol O. |one-fifth of air by volume. |in mild steel cylinders, | |At. wt. 16.00.|Water contains 88.88% of oxy- |and is used for the oxy- | |Valence II. |gen. The rocks of the earth’s |hydrogen blowpipe and in | |S. G. (liquid |crust contain about 45% in |medicine, besides for | |at B. P.) |combination, chiefly as sili- |chemical purposes. It is | |1.13. |cates. |necessary to support | |M. P. -218.4°.|PREP.--in the laboratory by |animal respiration and to | |B. P. -182.5°.|heating potassium chlorate |sustain ordinary combus- | | |(KClO₃). Commercially, from the|tion. It enters as a con- | | |air. |stituent into all oxides, | | |PROP.--a colorless, odorless, |most salts and many | | |tasteless, transparent gas, |organic compounds. | | |slightly heavier than air. At | | | |ordinary temperature and pres- | | | |sure, 100 volumes of water dis-| | | |solve 3 volumes of oxygen. It | | | |is very active chemically, com-| | | |bining directly with all but a | | | |few of the other elements to | | | |form oxides. Sulphur, phospho- | | | |rus, etc., burn much more | | | |vigorously in oxygen than in | | | |air. Liquid oxygen is magnetic.| | +--------------+-------------------------------+--------------------------+ |=Palladium.= |OCC.--along with platinum, and |Since it does not tarnish,| |Symbol Pd. |with gold in Brazil. |it is used for coating | |At. wt 106.7. |PREP.--by a complex series of |silver goods, and by | |Valence II. |processes from platinum ores. |dentists as a substitute | |and IV. |PROP.--a silvery, malleable and|for gold. | |S. G. 11.9. |ductile metal, related to | | |M. P. 1549°. |platinum, unlike which, how- | | | |ever, it is attacked by nitric | | | |acid. Under suitable conditions| | | |it can take up over 900 volumes| | | |of hydrogen. | | +--------------+-------------------------------+--------------------------+ |=Phosphorus.= |OCC.--as phosphates, such as |Red phosphorus is used in | |Symbol P. |apatite [CaF(PO₄)₃]; in bones, |the manufacture of | |At. wt. 31.04.|teeth, brain and seeds of |matches, as also is the | |Valence III. |plants. |compound P₄S₃. In the form| |and V. |PREP.--by reduction of calcium |of superphosphate of lime | |S. G. |phosphate by carbon in the |[CaH₂(PO₄)₂] phosphorus is| |white, 1.82. |electric furnace in presence of|an important artificial | |red, 2.25. |a suitable flux. |manure. The chlorides | |M. P. white, |PROP.--phosphorus exists in two|(PCl₃ and PCl₅) are much | |44°. |allotropic modifications: white|used in organic chemistry.| |B. P. 289°. |phosphorus is waxy in consis- | | | |tency, soluble in carbon bi- | | | |sulphide, evil smelling and | | | |poisonous; red phosphorus is a | | | |solid, insoluble in carbon bi- | | | |sulphide, odorless and not | | | |poisonous. White phosphorus has| | | |a low ignition temperature, | | | |hence its former use in | | | |matches. | | +--------------+-------------------------------+--------------------------+ |=Platinum.= |OCC.--free, alloyed with the |On account of its resis- | |Symbol Pt. |platinum metals, as nuggets in |tance to acids, platinum | |At. wt. 195.2.|alluvial sands in the Urals, |is much used for chemical | |Valence II. |California, etc. |vessels. Since platinum | |and IV. |PREP.--it is freed from the |has a coefficient of | |S. G. 21.48. |metals with which it is alloyed|expansion very close to | |M. P. 1753°. |by a complex series of proces- |that of glass, platinum | | |ses. |wires can be fused through| | |PROP.--a silvery, tenacious, |glass without danger of | | |ductile and malleable metal, |breakage on cooling. The | | |unaltered in moist air and un- |salts are used in photo- | | |attacked by any single common |graphy. | | |acid. Aqua regia, fused alka- | | | |lies, alkali nitrates and | | | |cyanides attack it, however. | | | |Platinum “sponge” and “black” | | | |are finely divided forms. | | +--------------+-------------------------------+--------------------------+ |=Potassium.= |OCC.--as sylvite (KCl), |An alloy with sodium is | |Symbol K. |carnallite (KCl, MgCl₂, 6H₂O); |used in filling high- | |At. wt. 39.10.|in plant and animal ashes, and |temperature thermometers. | |Valence I. |in many complex silicates. |Bengal saltpeter is the | |S. G. 0.86. |PREP.--by reduction or by |nitrate and is used in | |M. P. 62.5°. |electrolysis of fused potassium|pyrotechny, for gunpowder | |B. P. 762°. |hydroxide (KOH). |and as a preservative. The| | |PROP.--a silver-white, lustrous|iodide (KI) is used in | | |metal, as soft as wax, tarnish-|medicine. The chlorate, | | |ing instantly in moist air. |like the nitrate, is used | | |Chemically it is a very active |as a source of oxygen in | | |metal, decomposing water in the|pyrotechny and for match | | |cold and uniting violently with|heads. Caustic potash | | |the halogens, sulphur and |(KOH) has many chemical | | |oxygen. |applications. The cyanide | | | |(KCN) is used in gold ex- | | | |traction. | +--------------+-------------------------------+--------------------------+ |=Praseodym- |OCC.--with cerium and |The salts are leek-green | |ium.= |lanthanum. |in color, and their solu- | |Symbol Pr. |PREP.--by electrolysis of the |tions have characteristic | |At. wt. 140.9.|fused chloride. |absorption spectra. | |Valence III. |PROP.--a yellowish metal, re- | | |and IV. |maining untarnished in air. | | |S. G. 6.47. | | | |M. P. 940°. | | | +--------------+-------------------------------+--------------------------+ |=Radium=. |OCC.--in minute quantity in |The rays from radium com- | |Symbol Ra. |pitchblende and other uranium |pounds (such as RaBr₂, | |At. wt. 226.0.|minerals. |RaCl₂, RaCO₃) act destruc-| |Valence II. |PREP.--the metal has recently |tively on living tissues | |M. P. 700°. |been isolated; the bromide is |and on bacteria. One gram | | |separated from the barium |of radium in any of its | | |bromide prepared from pitch- |compounds gives off about | | |blende by fractional crystalli-|100 calories of heat per | | |zation. |hour. | | |PROP.--in all of its compounds,| | | |the metal has the power of | | | |emitting certain radiations. | | | |These can pass through matter | | | |that is opaque to light, render| | | |air a conductor, affect a | | | |photographic plate and cause a | | | |zinc-sulphide screen to | | | |fluoresce visibly. | | +--------------+-------------------------------+--------------------------+ |=Rhodium.= |OCC.--in the ores of platinum. |The red chloride (RhCl₃) | |Symbol Rh. |PREP.--by a complex series of |is formed by the action of| |At. wt. 102.9.|processes from platinum ores. |chlorine upon the metal. | |Valence II., |PROP.--a silvery, malleable and| | |III. and IV. |ductile metal, not tarnishing | | |S. G. 12.1. |in air and not attacked by aqua| | |M. P. 1970°. |regia. | | +--------------+-------------------------------+--------------------------+ |=Rubidium.= |OCC.--the salts are associated |The compounds show charac-| |Symbol Rb. |with salts of potassium. |teristic flame-spectra, | |At. wt. 85.45.|PREP.--similar to that of |and were recognized as | |Valence I., |potassium. |those of a new element | |III. and V. |PROP.--a silver-white metal |spectroscopically by | |S. G. 1.53. |resembling potassium, like |Bunsen. | |M. P. 38.5°. |which it attacks water vigor- | | |B. P. 69.8°. |ously. | | +--------------+-------------------------------+--------------------------+ |=Ruthenium.= |OCC.--in the ores of platinum. |The following oxides are | |Symbol Ru. |PREP.--by a complex series of |known: Ru₂O₃, RuO₂, RuO₄, | |At. wt. 101.7.|processes from platinum ores. |as well as salts corre- | |Valence III., |PROP.--a hard, white, brittle |sponding to RuO₃ and | |IV., VI., VII.|metal, oxidized when heated in |Ru₂O₇. | |and VIII. |air, scarcely attacked by aqua | | |S. G. 12.1. |regia. | | |M. P. above | | | |1950°. | | | +--------------+-------------------------------+--------------------------+ |=Samarium.= |OCC.--in the mineral |The salts are topaz-yellow| |Symbol Sa. |samarskite. |in color, and are similar | |At. wt. 150.4.|PREP.--by electrolysis of the |to those of lanthanum. | |Valence II. |chloride. | | |and III. |PROP.--a whitish-gray metal, | | |S. G. ca. 7.7.|tarnishing in air. | | |M. P. 1300 to | | | |1400°. | | | +--------------+-------------------------------+--------------------------+ |=Scandium.= |OCC.--in the minerals euxenite |The chloride (ScCl₃) shows| |Symbol Sc. |and gadolinite. |a characteristic spark | |At. wt. 44.1. |PREP.--the metal has not been |spectrum. | |Valence III. |isolated. | | | |PROP.--the existence of this | | | |element, whose oxide was dis- | | | |covered in 1879, was predicted | | | |by Mendeléeff in 1869. | | +--------------+-------------------------------+--------------------------+ |=Selenium.= |OCC.--free in some specimens of|Selenium cells are used as| |Symbol Se. |sulphur, and in combination |indicators of intensity of| |At. wt. 79.2. |with lead, iron and other |illumination. The com- | |Valence II., |metals, as in pyrites. |pounds strongly resemble | |IV. and VI. |PREP.--(amorphous) by reducing |those of sulphur. Hydrogen| |S. G. |selenious acid (H₂SiO₃) by |selenide is an evil- | |amorphous |sulphur dioxide. |smelling inflammable gas. | |4.26. |PROP.--three varieties are |Selenic acid (H₂SeO₄) is a| |monoclinic |known: (1) red amorphous, |more powerful oxidizer | |4.47 |soluble in carbon bisulphide, |than sulphuric acid and | |hexagonal 4.8.|from which it is deposited as |dissolves gold. | |M. P. |(2) red translucent monoclinic | | |amorphous 50°.|crystals, soluble in carbon bi-| | |monoclinic 170|sulphide, (3) blue-gray metal- | | |to 180°. |lic selenium, insoluble in | | |hexagonal |carbon bisulphide. This last | | |217°. |form conducts electricity many | | |B. P. 688°. |times better when exposed to | | | |light, and the better the | | | |brighter the light. | | +--------------+-------------------------------+--------------------------+ |=Silicon.= |OCC.--silicon dioxide (SiO₂) |The “pigs” of silicon made| |Symbol Si. |occurs as flint, quartz, quartz|at Niagara are used in | |At. wt. 28.3. |sand, etc. The igneous rocks |steel-making. The ornamen-| |Valence IV. |are composed largely of sili- |tal varieties of quartz | |S. G. |cates, and this element consti-|find uses as gemstones, as| |amorphous 2.3.|tutes over 25% of the earth’s |do several natural sili- | |crystalline |crust. |cates. Silicon carbide, | |2.34. |PREP.--by reducing sand with |“carborundum” (SiC), is | |M. P. 1458°. |coke in the electric furnace. |used as an abrasive. | |B. P. ca. |PROP.--amorphous silicon is a |Sodium silicate solution | |3500°. |brown powder that burns when |is “water glass,” used to | | |heated in air. Crystalline |protect sandstone and to | | |silicon forms black needles. It|preserve eggs. Common | | |is less active than the amor- |glass is a mixture of | | |phous variety and is attacked |sodium and calcium sili- | | |only slowly by a mixture of |cates. | | |hydrofluoric and nitric acids. | | | |It unites with fluorine, how- | | | |ever, at ordinary temperatures.| | +--------------+-------------------------------+--------------------------+ |=Silver.= |OCC.--native, as sulphide |It is employed for arti- | |Symbol Ag. |(Ag₂S) often associated with |cles of use and of orna- | |At. wt. |galena; chloride (AgCl), etc. |ment and for coinage. | |107.88. |PREP.--from lead by the |U. S. sterling silver con-| |Valence I. |Pattison or Parkes process; |tains 90% silver and 10% | |S. G. 10.53. |from the ores by the Mexican |copper. Lunar caustic is | |M. P. 960°. |and other processes. |silver nitrate. This salt | |B. P. 1955°. |PROP.--a white, highly lus- |and the halides of silver | | |trous, tough, very ductile and |are extensively used in | | |malleable metal, the best con- |photography. For electro- | | |ductor of heat and electricity |plating, a bath of potas- | | |known. Liquid silver dissolves |sium argenticyanide | | |oxygen. It is unaffected by the|[KAg(CN)₂] is used. | | |oxygen of moist air, and its | | | |tarnishing is due to the action| | | |of hydrogen sulphide. It dis- | | | |solves in dilute nitric and in | | | |concentrated hot sulphuric | | | |acid. | | +--------------+-------------------------------+--------------------------+ |=Sodium.= |OCC.--in the sea as chloride |The metal is used in the | |Symbol Na. |(NaCl); in salt deposits as |manufacture of several | |At. wt. 23.00.|chloride, borate, nitrate; in |chemicals. Sodium chloride| |Valence I. |many complex silicates in |(NaCl) is a necessity of | |S. G. 0.97. |rocks. |life to most animals; and | |M. P. 965°. |PREP.--by electrolysis of fused|is used in the manufacture| |B. P. 883°. |sodium hydroxide (NaOH). |of hydrochloric acid, | | |PROP.--a silver-white metal, as|chlorine and sodium com- | | |soft as wax, that may be welded|pounds. Sodium carbonate | | |at ordinary temperature. Like |(NaCO₃, 10H₂O) or washing | | |potassium it is very active, |soda, and sodium hydroxide| | |uniting directly with many |(NaOH) are used for | | |other elements, and attacking |cleaning, and in the manu-| | |water vigorously in the cold. |facture of soap and chemi-| | | |cals. Baking soda is | | | |sodium bicarbonate | | | |(NaHCO₃). The sulphate | | | |(Na₂SO₄, 10H₂O) is known | | | |as Glauber’s salt; the | | | |thiosulphate, by photo- | | | |graphers, as “hypo.” | +--------------+-------------------------------+--------------------------+ |=Strontium.= |OCC.--as strontianite (SrCO₃) |The nitrate and chlorate | |Symbol Sr. |and celestine (SrSO₄). |are used in pyrotechny for| |At. wt. 87.63.|PREP.--by electrolysis of the |red fire. All volatile | |Valence II. |fused chloride. |compounds color the Bunsen| |S. G. 2.55. |PROP.--a white metal, softer |flame red. | |M. P. ca. |than calcium and harder than | | |800°. |sodium, tarnishing to a yellow | | | |tint. Like calcium it is active| | | |enough to attack water vigor- | | | |ously in the cold. | | +--------------+-------------------------------+--------------------------+ |=Sulphur.= |OCC.--native, in combination |Sulphur is used to prepare| |Symbol S. |with most metals as sulphides, |sulphur dioxide (SO₂), | |At. wt. 32.06.|and with some metals as sul- |which is used in making | |Valence II., |phates. |sulphuric acid and sul- | |IV. and VI. |PREP.--by melting the free sul-|phites, and for bleaching;| |S. G. |phur away from the rocky |also for vulcanizing | |rhombic 2.06. |matrix, and subsequent purifi- |rubber and in the manufac-| |monoclinic |cation by distillation. |ture of black gunpowder, | |1.96. |PROP.--natural sulphur is rhom-|fireworks and matches. | |M. P. |bic in crystalline form, yel- |Sulphuric acid (H₂SO₄) is | |rhombic |low, brittle, of vitreous |to chemical industry what | |112.4°. |luster, and a poor conductor of|iron is to engineering. | |monoclinic |heat and electricity. This and | | |119°. |the monoclinic variety are | | |B. P. 444.9°. |soluble in carbon bisulphide, | | | |while amorphous sulphur is not.| | | |When heated, sulphur unites | | | |directly with most of the other| | | |elements. | | +--------------+-------------------------------+--------------------------+ |=Tantalum.= |OCC.--in tantalite and many |The metal is used for | |Symbol Ta. |other rare minerals. |filaments for electric | |At. wt. 181.5.|PREP.--by the action of sodium |lamps, which possess twice| |Valence II., |on sodium tantalofluoride |the efficiency of the | |IV. and V. |(Na₂TaF₇). |carbon filament lamp. | |S. G. 16.6. |PROP.--a hard, silver-white | | |M. P. bet. |metal, ductile and malleable | | |2250° and |when hot, of very high tensile | | |2300°. |strength. The hot metal can ab-| | | |sorb 740 volumes of hydrogen. | | | |It is not attacked by aqua | | | |regia. | | +--------------+-------------------------------+--------------------------+ |=Tellurium.= |OCC.--free and as tellurides. |The compounds find few ap-| |Symbol Te. |PREP.--by reducing tellurious |plications. Telluric acid | |At. wt. 127.5.|acid (H₂TeO₃) by means of sul- |(H₆TeO₆) has basic as well| |Valence II., |phur dioxide. |as acid characters, in | |IV. and VI. |PROP.--the crystalline variety |keeping with the position | |S. G. cryst. |is white, has metallic luster, |of the element between | |6.2. |and conducts heat and electri- |metals and nonmetals. | |M. P. cryst. |city. The precipitated variety | | |455°. |is black and of lower density. | | |B. P. 1400°. |The element is related to sul- | | | |phur but is more metallic in | | | |character. | | +--------------+-------------------------------+--------------------------+ |=Terbium.= |OCC.--in gadolinite, |The salts show no absorp- | |Symbol Tb. |samarskite, and other rare |tion spectrum. | |At. wt. 159.2.|minerals. | | |Valence III. |PREP.--the metal has not been | | | |prepared. | | +--------------+-------------------------------+--------------------------+ |=Thallium.= |OCC.--in crookesite, and in |It forms two sets of | |Symbol Tl. |small quantities in many |salts, the thallous (e.g.,| |At. wt. 204.0.|samples of iron pyrites. |TlCl) and the thallic | |Valence I., |PREP.--it is precipitated by |(e.g., TlCl₃). All the | |and II. |zinc from a solution obtained |compounds show a charac- | |S. G. 11.8. |by suitable treatment of the |teristic green line in the| |M. P. 303. |flue dust from sulphuric acid |spectrum. | |B. P. 1515°. |works. | | | |PROP.--a bluish-white, lead- | | | |like metal, rather soft, malle-| | | |able, but of low tensile | | | |strength. It decomposes water | | | |rapidly at red heat, and dis- | | | |solves in dilute acids. | | +--------------+-------------------------------+--------------------------+ |=Thorium.= |OCC.--in monazite sand. |The nitrate [Th(NO₃)₄, | |Symbol Th. |PREP.--by reducing potassium |6H₂O] is used in making | |At. wt. 232.4.|thorium chloride with sodium, |Welsbach incandescent | |Valence IV. |or by electrolysis of the |mantles, which consist of | |S. G. 11.0. |chloride in a mixture of fused |99% of ThO₂. All the com- | |M. P. above |potassium and sodium chlorides.|pounds are radio-active. | |1700°. | | | +--------------+-------------------------------+--------------------------+ |=Thullium.= |OCC.--in gadolinite and other |The salts are of a pale | |Symbol Tm. |yttrium minerals. |bluish color which is | |At. wt. 168.5.|PROP.--a metal with the color |destroyed very easily by | |Valence III. |of nickel, that can be burnt in|minute quantities of | |M. P. 1700°. |air. Hydrochloric acid attacks |erbium. | | |it but slowly. | | +--------------+-------------------------------+--------------------------+ |=Tin.= |OCC.--as cassiterite (SnO₂). |Large quantities of tin | |Symbol Sn. |PREP.--after roasting, the ore |are used in the tinning of| |At. wt. 118.7.|is reduced by heating with |iron for tinplate. It is a| |Valence II. |carbon. |constituent of the alloys | |and IV. |PROP.--a silver-white, rather |Britannia metal, pewter, | |S. G. |soft, very malleable and duc- |solder, bronze, etc. Tin | |white 7.3. |tile metal, practically un- |forms two sets of salts, | |gray 5.7. |changed in air. When heated, it|stannous (e.g., SnCl₂) and| |M. P. 231.8°. |may be burned in air. Dilute |stannic (e.g., SnCl₄). | |B. P. 2275°. |nitric acid is the only dilute |“Pink salt” [(NH₄)₂SnCl₆] | | |acid that attacks it rapidly. |is used in dye. “Mosaic | | |When kept long at temperatures |gold” is SnS₂. | | |below zero Centigrade, ordinary| | | |tin changes to a brittle, gray,| | | |powdery modification. This form| | | |is the stable one below 20°. | | +--------------+-------------------------------+--------------------------+ |=Titanium.= |OCC.--as rutile (TiO₂) and in |The element is very widely| |Symbol Ti. |titanic iron ore (FeTiO₃). |disseminated, though in | |At. wt. 48.1. |PREP.--by reducing the chloride|small quantity. It is con-| |Valence II., |(TiCl₄) by means of sodium. |tained in the ashes of all| |III. and IV. |PROP.--a hard, brittle metal, |plants. | |S. G. 4.5. |resembling polished steel in | | |M. P. below |appearance, that may be forged | | |1850°. |at a low red heat. It dissolves| | | |in dilute sulphuric acid, and | | | |decomposes steam at 800°. It | | | |unites easily with nitrogen. | | +--------------+-------------------------------+--------------------------+ |=Tungsten.= |OCC.--as wolfram (FeWO₄) and as|The metal is used for the | |Symbol W. |scheelite (CaWO₄). |filaments of incandescent | |At. wt. 184.0.|PREP.--by reducing tungstic |electric lamps, giving an | |Valence II., |acid (H₂WO₄) by carbon at a high|efficiency of 1.3 watts | |IV., V. and |temperature. |per candle power. Tungsten| |VI. |PROP.--a hard, brittle, gray |steel has 5% W. Sodium | |S. G. 19.3. |metal, attacked by chlorine |tungstates are used as | |M. P. 3177°. |only at 250°, although it can |mordants in dyeing. | |B. P. ca. |be caused to burn in air. It is| | |3700°. |slowly acted upon by dilute | | | |acids and even by water. | | +--------------+-------------------------------+--------------------------+ |=Uranium.= |OCC.--as pitchblende, which |All the compounds of ura- | |Symbol U. |contains U₃O₈. |nium are radioactive in | |At. wt. 238.2.|PREP.--by reducing the oxides |proportion to their ura- | |Valence III., |with aluminum. |nium content. Glass to | |IV., V. and |PROP.--a white, lustrous metal,|which uranium compounds | |VIII. |tarnishing in air and attacking|have been added shows a | |S. G. 18.7. |water slowly in the cold. It |greenish-yellow fluores- | |M. P. ca. |combines directly with many of |cence. | |1500°. |the other elements. | | +--------------+-------------------------------+--------------------------+ |=Vanadium.= |OCC.--in a few rather rare |Vanadium added to steel in| |Symbol V. |minerals. |even small quantity (0.2%)| |At. wt. 51.0. |PREP.--by reduction of the di- |increases the tenacity and| |Valence II., |chloride (VCl₂) in hydrogen. |elastic limit without | |III., IV. and |PROP.--a silver-white, lustrous|reducing the ductility. | |V. |metal, harder than quartz. It | | |S. G. 5.7. |does not tarnish nor attack | | |M. P. ca. |water at ordinary temperatures,| | |1715°. |but can be burnt in oxygen. | | +--------------+-------------------------------+--------------------------+ |=Xenon.= |OCC.--in minute quantity in the|It forms no compounds. | |Symbol Xe. |air, less than one volume in | | |At. wt. 130.2.|100 million. | | |Valence 0. |PREP.--by fractionation of | | |B. P. -109°. |liquid argon. | | |S. G. (liquid |PROP.--a transparent, colorless| | |at B. P.) |and odorless gas, very inert | | |3.82. |like its congener argon. It is | | | |the densest of the argon | | | |family. | | +--------------+-------------------------------+--------------------------+ |=Ytterbium= |OCC.--in gadolinite, euxenite |The compounds show a char-| |(Neoytter- |and other rare minerals. |acteristic spark spectrum.| |bium). |PREP.--the metal has not been | | |Symbol Yb. |isolated. | | |At. wt. 173.5.| | | |Valence III. | | | +--------------+-------------------------------+--------------------------+ |=Yttrium.= |OCC.--in gadolinite, euxenite |The chloride yields a | |Symbol Y. |and other rare minerals. |characteristic, though | |At. wt. 88.9. |PREP.--by electrolysis of |complex, spectrum. | |Valence III. |sodium yttrium chloride. | | |S. G. 3.8. |PROP.--a gray, lustrous metal. | | +--------------+-------------------------------+--------------------------+ |=Zinc.= |OCC.--as zinc blende (ZnS), |Sheet zinc is used for | |Symbol Zn. |calamine (ZaCO₂), zincite |roofs and gutters. Iron is| |At. wt. 65.37.|(ZnO), etc. |galvanized by dipping it | |Valence II. |PREP.--after roasting, the ore |in molten zinc, and so | |S. G. 6.9 to |is reduced by coal, the metal |protected from rusting. | |7.2. |distilling off. |Zinc is used for galvanic | |M. P. 419.3°. |PROP.--a bluish-white, lus- |batteries and, alloyed | |B. P. 906°. |trous, brittle metal, that is |with copper, to make | | |malleable and ductile at 120°. |brass. The salts are used | | |It tarnishes in moist air, |in medicine; the chloride | | |attacking water slowly in the |and sulphate antiseptic | | |cold and rapidly when heated in|solutions. | | |steam. It dissolves in dilute | | | |acids and in sodium hydroxide | | | |solution. | | +--------------+-------------------------------+--------------------------+ |=Zirconium.= |OCC.--as zircon (ZrSiO₄). |The oxide is contained in | |Symbol Zr. |PREP.--by reducing the oxide |some incandescent gas | |At. wt. 90.6. |(ZrO₂) with carbon in the elec-|mantles. | |Valence IV. |tric furnace. | | |S. G. 6.4. |PROP.--a hard, gray metal, re- | | | |maining bright in air and only | | | |slowly oxidized at a white | | | |heat. It is dissolved by aqua | | | |regia and by caustic potash | | | |solution. | | +--------------+-------------------------------+--------------------------+