Element Boron, B, Metalloid. Among the non-metallic elements, boron. Containing carbon, and obtained from the two elements at a very high temperature, is of a similar character, and also possesses an adamantine hardness. This also ought most probably to be regarded as a solid solution, and not as a chemical compound. The combining weight of boron is B. Have been known of for thousands of years. Century a substance was disengaged from burah. Which was called boronic acid. And Davy called it boron.

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Element Lithium, Li, Alkali Metal. From the compounds of the other alkali metals, those of lithium were distinguished by Arfvedson in 1817. Elementary lithium was first prepared in 1855 by Bunsen and Matthiessen, by the electrolysis of the chloride. Like the other alkali metals, lithium forms a monovalent, colourless ion Li. He also showed that this element is found within the minerals spodumene. By its geochemical properties lithium belongs.

Element Magnesium, Be, Alkaline Earth Metal. Magnesium bears the same relation to calcium as sodium does to potassium. This relation finds expression not only in the values of the combining weights, but also in the similarities to the other members of the group. This is particularly well seen in the fact that magnesium. Is now manufactured in very large amount by electrolysis, and is used for various purposes. It is a white, rather tough metal, which keeps fairly well in the air; it is scarcely attac.

Element Sodium Na, Alkali Metal. The chemical relations of sodium. Are very similar to those of potassium, so that for chemical purposes the one metal can in most cases replace the other. This holds good especially for those reactions in which the ions come into account. The reason of this is that natrion also represents a far more stable state than metallic sodium. Would die out by reason of the readily occurring lack of these. Cases of this have occurred, especially in former geological periods, and ha.

Element Aluminium, Al, Poor Metal. Of all the light metals, aluminium. It forms a constituent of almost all crystalline silicate rocks; and of the secondary formations, the clays and slate formations are formed from aluminium silicate. A knowledge of the compounds of this metal, therefore, extends back as far as chemical knowledge at all can be traced. While, even at comparatively high temperatures, massive aluminium is only superficially and inappre.

Element Hydrogen, H, Non Metal. All combustible substances are compounds. The phlogiston theory remained unrefuted for about fif.