Dobereiner's Periodic Table
Definition - What does Dobereiner's Periodic Table mean?
Johann Dobereiner (1780-1849) was a German chemist whose observations of certain chemical elements contributed to the modern periodic table. Between 1817 and 1829, Dobereiner discovered that the atomic weight of the element strontium was midway between the weights of calcium and barium. This prompted him to group other elements into groups of three, or triads. Dobereiner's experiments showed the importance of sorting elements according to their relative atomic weights.
Corrosionpedia explains Dobereiner's Periodic Table
Before the creation of the modern periodic table, scientists were constantly working on ways to arrange chemical elements into some sort of logical order. Dobereiner's triads were one of the earliest attempts at systematically organizing elements.
After forming the relationship between strontium, calcium and barium, by 1829 Dobereiner had discovered two other triads: chlorine, bromine and iodine, and lithium, sodium and potassium. However, the accuracy of atomic weight measurements at the time was relatively poor, which hindered the classification of more elements.
Since then, the discovery of atomic numbers revolutionized the way scientists organize chemical elements, and forms the basis of the periodic table used today.