Element Antimony, Sb, Metalloid. Is allied on the one hand to bismuth, and on the other, to arsenic and phosphorus. It therefore forms a transition element between the metals and the non-metals, but is still essentially on the side of the metals. Its combining weight is Sb. Probably, therefore, we are dealing with a mixture of different kinds of vapour, perhaps Sb. Is known from high antiquity. Oriental countries were familiar with Antimony.

Element Arsenic, As, Metalloid. In accordance with its smaller combining weight, arsenic. Deviates still more than antimony from the type of the metals, and exhibits greater similarity to the non-metal phosphorus; at the same time the tendency to form acid compounds increases. In fact the resemblance of arsenic to phosphorus is so great that it might also have been treated along with that element among the non-metals. If the vapour of arsenic. At the same time, other kinds of amorphous arsenic are formed.

Element Bismuth, Bi, Poor Metal. For the purposes of analysis, bismuth. Bismuth readily forms alloys with other metals whereby, in accordance with the general law, the melting point sinks. The combining weight of bismuth has been determined by weighing the metal and the oxide obtained from it. It is not known with perfect certainty, and we shall take it as Bi.

Element Bromine, Br, Halogene. The vapour of bromine is very heavy. If a small bulb filled with bromine be broken, or if, by means of a pipette, a drop of bromine be placed at the bottom of a large, empty bottle, it is seen that the brown-yellow vapour produced remains at the bottom and sways heavily when the bottle is moved. Only after standing undisturbed for a considerable time does the bromine.

Element Iodine, I, Halogene. Is allied to chlorine and bromine, and forms a third similar element. Of the three, it has the highest combining weight, amounting to 126. 86, and its properties show deviations from those of bromine chiefly in the same direction as those of bromine deviate from chlorine. Vapour is very considerable, being about nine times as great as that of air. The molar weight is 254 and the vapour has, therefore, the formula I.

Element Polonium, Po, Metalloid. 7 natural metalloid polonium isotopes. With mass numbers 210-212, 214-216 and 218 are found as members of radioactive decay series of uranium, actinouranium and thorium. Is a rare element; its crustal abundance is 2x10. Is a soft metal with silver luster, density 9. Outer electron shell configuration is 6 s. As well as hydroxide PoO.

Element Selenium, Se, Non Metal. Whereas the amorphous selenium does not conduct the electric current to a measurable extent, the property of conductivity is possessed by the crystalline form. Hydrogen selenide is the hydrogen acid of selenium in the same sense as hydrogen sulphide is the hydrogen acid of sulphur; its aqueous solution contains the ions Se. By heating selenium with iron filings, and to treat this with hydrochloric acid. In a manner perfectly analogous to the prep.