Tellurium Sentence Examples

The presence of tellurium in native sulphur is rare, but is known in certain specimens from Japan.

The rare element tellurium has been discovered in New South Wales at Bingara and other parts of the northern districts, as well as at Tarana, on the western line, though at present in such minute quantities as would not repay the cost of working.

Vauquelin in 1797, and Klaproth's investigation of tellurium in 1798, the next important series of observations was concerned with platinum and the allied metals.

Tellurium appears to give a pale pink tint.

It may conveniently be extended to similar mixtures of sulphur and selenium or tellurium, of bismuth and sulphur, of copper and cuprous oxide, and of iron and carbon, in fact to all cases in which substances can be made to mix in varying proportions without very marked indication of chemical action.

The presence of minute quantities of cadmium, lead, bismuth, antimony, arsenic, tin, tellurium and zinc renders gold brittle, 2 ' 0 15th part of one of the three metals first named being sufficient to produce that quality.

Of the minerals containing gold the most important are sylvanite or graphic tellurium (Ag, Au) Tee, with 24 to 26%; calaverite, AuTe2, with 42%; nagyagite or foliate tellurium (Pb, Au)16 Sba(S, Te)24, with 5 to 9% of gold; petzite, (Ag, Au) 2 Te, and white tellurium.

It appears that amalgamation is often impeded by the tarnish found on the surface of the gold when it is associated with sulphur, arsenic, bismuth, antimony or tellurium.

This is smelted with rich gold ores, notably those containing tellurium, for white metal or regulus; and by a following process of partial reduction analogous to that of selecting in copper smelting, " bottoms " of impure copper are obtained in which practically all the gold is concentrated.

It is necessary to remove as completely as possible any lead, tin, bismuth, antimony, arsenic and tellurium, impurities which impair the properties of gold and silver, by an oxidizing fusion, e.g.

The slight variations in specific gravity are due to the presence of small amounts of arsenic, sulphur or tellurium, or to enclosed impurities.

Bismuth forms compounds similar to the trisulphide with the elements selenium and tellurium.

Small quantities are occasionally met with in iron pyrites, and hence tellurium is found with selenium in the flue dust, or chamber deposits of sulphuric acid works.

The crude element is treated with aqua regia and then evaporated with an excess of hydrochloric acid, the solution diluted and the tellurium precipitated by a current of sulphur dioxide.

Tellurium is a brittle silvery-white element of specific gravity 6.27.

An amor phous form is obtained when tellurium is precipitated from its solutions by sulphur dioxide, this variety having a specific gravity 6.015.

When heated in air, tellurium burns, forming the dioxide Te02.

It is soluble in water, the solution gradually decomposing with deposition of tellurium; it also decomposes on exposure to light.

They are both obtained by passing chlorine over tellurium, the product being separated by distillation (the tetrachloride is the less volatile).

The dioxide is formed by burning tellurium in air or xxvi.

Tellurous acid, H 2 TeO 3, is obtained when the tetrachloride is decomposed by water, or on dissolving tellurium in nitric acid and pouring the solution into water.

Telluric acid, H2Te04, is obtained in the form of its salts when tellurium is fused with potassium carbonate and nitre, or by the oxidizing action of chlorine on a tellurite in alkaline solution.

A considerable amount of work has been done on determinations of the atomic weight of tellurium, the earlier results giving the value 128.

These substances, and also carbon, sulphur, selenium and tellurium, render the metal very brittle.

Antimony, bismuth, selenium, tellurium, chromic iron ore, tin, nickel, cobalt, vanadium, titanium, molybdenum, uranium and tantalum are produced in the United States in small amounts, but such production in several cases has amounted to only slight discoveries, and in general they are of little importance in the market.

The gold is often found in conjunction with tellurium (first discovered in Transylvania in 1782) and is extracted principally at Nagyag, Kapnik-Banya, Zalatna and V6rbspatak.

Crookes presumed that his thallium was something of the order of sulphur, selenium or tellurium; but Lamy, who anticipated him in isolating the new element, found it to be a metal.

The impurities contained in coarse-copper are mainly iron, lead, zinc, cobalt, nickel, bismuth, arsenic, antimony, sulphur, selenium and tellurium.

The principles have long been known on which is based the electrolytic separation of copper from the certain elements which generally accompany it, whether these, like silver and gold, are valuable, or, like arsenic, antimony, bismuth, selenium and tellurium, are merely impurities.

The commercial element usually contains a certain amount of sulphur, and some tellurium, and various methods have been devised for its purification.

The most common additives are sulfur and lead, other elements used include tellurium, selenium and bismuth.

The tellurides of the alkali metals immediately decompose on exposure to air, with liberation of tellurium.

According to its position in the periodic classification of the elements one would expect its atomic weight to be less than that of iodine, instead of approximately equal, and on this account many efforts have been made to isolate another element from tellurium compounds, but none have as yet been successful.

Marckwald (Ber., 1903, 36, p. 2662) showed that the Joachimsthal pitchblende yields tellurium and a minute quantity of the strongly radioactive polonium which is precipitated by bismuth (see Radioactivity).

Arsenic possesses a steel-grey colour, and a decided metallic lustre; it crystallizes on sublimation and slow condensation in rhombohedra, isomorphous with those of antimony and tellurium.

The precipitated tellurium is then fused with potassium cyanide, the melt extracted with water and the element precipitated by drawing a current of air through the solution and finally distilled in a current of hydrogen.