1 gen 1829 anni - John Dobereiner P2

Descrizione:

John Dobereiner was a German scientist who developed the Law of Triads. Each was a group of three elements similar to each other. In 1829, he noticed that bromine, element that fell about halfway between chlorine and iodine in atomic weight, also seemed halfway between them in its other properties. Other “triads” that he discovered were: calcium, strontium, and barium, and sulfur, selenium, and tellurium.

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