Answer:
Dobereiner’s triad arranged elements with similar properties into groups.
- Johann Dobereiner, a German chemist, classified different groups of three elements into groups known as triads in 1829.
- Lithium, sodium, and potassium were one such triad. Physical and chemical properties were used to generate triads. Dobereiner discovered a pattern in the atomic masses of such three elements, as well as other triads.