How did Dobereiner classify the elements?
Answers
Explanation:
During the 1820s Döbereiner’s experiments with the ignition of hydrogen on contact with powdered platinum led the Swedish chemist J.J. Berzelius to develop the concept of catalysis. Toward the end of the decade Döbereiner found that the properties of bromine, a liquid, seem halfway between those of chlorine gas and the solid iodine. He recalled a comparable graduation of properties in two other sequences, i.e. calcium, strontium, barium; and sulfur, selenium, tellurium. Each of Dobereiner's triads was a group of three elements. The appearance and reactions of the elements in a triad were similar to each other. He showed that in each triad the mean of the lightest and heaviest atomic weights approximated the atomic weight of the middle element. But he could not substantiate his hypothesis with a sufficient number of triads, and his findings were regarded in his time as merely interesting curiosities.