Triadas de johann dobereiner biography

Historical scientific theory

In the history of the periodic table, Döbereiner's triads were an early attempt to sort the elements into some logical order and sets based on their physical properties.

They are analogous to the groups (columns) on the modern periodic table.

Triadas de johann dobereiner biography

53 elements were known at his time.

In 1817, a letter by Ferdinand Wurzer [de] reported Johann Wolfgang Döbereiner's observations of the alkaline earths; namely, that strontium had properties that were intermediate to those of calcium and barium.^[1]

"In der Gegend von Jena (bei Dornburg) … Schwerspaths seyn möchte." (In the area of Jena (near Dornburg) it is known that celestine has been discovered in large quantities.

This gave Mr. Döbereiner cause to inquire rigorously into the stoichiometric value of strontium oxide by a great series of experiments. It turned out that it [i.e., the molar weight of strontium oxide] – if that of hydrogen is expressed by 1 or th