CLASSIFICATION OF METALS. 113 



b. Ir\ combination only. 

 Potassium, "] 



Sodium, L Chiefly as chlorides or silicates. 



Lithium, 



Barium, as sulphate. 

 Calcium, | 



Strontium, j. As carbonates, sulphates, silicates. 

 Magnesium, 

 Aluminium, in silicates. 

 Iron, ") 



Zinc, }. As oxides, carbonates, sulphides 



Cadmium, 

 Arsenic, ~| 



Antimony, 

 Lead, 



Cobalt, j" Chiefly as sulphides. 



Nickel, 

 Molybdenum, 



Chromium, ~] 



Manganese, L Chiefly as oxides. 



Tin, j 



Classification of metals. 



Light metals. Heavy metals. 



Sp. gr. from 0.6 to 4. Sp. gr. from 6 to 21.5. 



Sulphides soluble in water. Sulphides insoluble in water. 



Light metals. 



Earth metals. Alkaline earth metals. Alkali-metals. 



Al, and many rare metals. Ba, Ca, Sr, (Mg). K, Na, Li, (NH 4 ). 



Oxides insoluble. Oxides soluble ; Oxides, carbonates, and 



Carbonates insoluble. most salts soluble. 



Heavy metals. 



Arsenic group. Lead group. Iron group. 



As,Sb,Sn,Au, Pt, Mo. Pb, Cu, Bi, Ag, Hg, Cd, Fe, Co, Ni, Mn, Zn, Cr. 



, ' Sulphides soluble in 



Sulphides insoluble in dilute acid^s. dilute acids. 



Sulphides soluble in am- Sulphides insoluble in 

 monium sulphide. ammonium sulphide. 



Properties of metals. All metals have a peculiar lustre known 

 as metallic lustre, and all are good conductors of heat and 

 electricity. The color of most metals is white, grayish- or 



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