Platinum, atomic weight properties

Occurrence and History of Platinum--Proparatioi) -Punlioulimi Physical Properties—Volatilisation -Diffusion of Cases Solubility of (laMes Chemical Properties - -Catalytic Activity -Passivity Crystalline Platinum —Colloidal Platinum — Platinum Black Platinum Mpongo Explosive Platinum —Atomic Weight — Uses Buhstitutes Alloys Platinum Amalgam. 

A study of the chemical properties of iridium and its compounds shows that, whilst closely resembling platinum in many respects, it forms a fitting link between that element and osmium. With an atomic weight intermediate in value between 190-9 (at. wt. of osmium) and 195-2 (at. wt. of platinum), iridium falls into a suitable position in the Periodic Table where these analogies are recognised. 

The Grouping of Elements into Triads—Atomic Weights of the Elements— General Properties of tho Elements—Comparative Study of Iron, Cobalt, and Nickel—Their Position in tho Periodic Table—Comparative Study of Iron, Ruthenium, and Osmium—Comparative Study of Cobalt, Rhodium, and Iridium—Comparative Study of Nickel, Palladium, and Platinum. 

Uralium, byGuyard in 1869, again from platinum ores it had a density of 20-25 and an atomic weight of 187 these are in general accord with those of rhenium D = 21-04 and At. Wt. 186-31. But in its chemical and other physical properties there was less similarity. 

Such are nickel and cobalt, whose atomic weights are very close to each other, ihodium, ruthenium and palladium on the rate hand, iridium, osmium and platinum on the other ate also elements which closely resemble one another, and which have very similar atomic weights. Iron and manganese have similar properties and their atomic weights are also very similar ... 

Elements which are similar as regards their chemical properties have atomic weights which are either of nearly the same value (platinum, iridium, osmium), or which increase regularly (potassium, rubidium, caesium). 

The system became a resounding success when the deductions which were drawn from it were confirmed by experiments in rapid succession the selection of the atomic weight with respect to the known number of equivalents, as in the case of indium and uranium the change in the order, regardless of the valid atomic weights, such as the platinum group and, last but not least, the prediction of new elements and their chemical properties which were proved true with the... 

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