JOHN DOBEREINER

 

He was a German chemist. He is known for his periodic law for chemical elements. In his childhood, he could hardly attend school in formal manner. But he used to read widely and attend lectures related to science. These activities made him a professor of university of Jena in 1810. He found that, average of atomic masses of lithium and potassium was close to the atomic mass of sodium. Atomic mass of calcium was found to be equal to the average atomic masses of strontium and barium. Similar observations were made with sulphur, selenium and tellurium and also chlorine, bromine and iodine. Similarly densities for these triads followed a similar trend. The sets of three elements were known as Dobereiner’s Triads.