In the year 1817 ______ tried to arrange elements with similar properties into groups.

Dobereiner

The correct answer is option 3. Dobereiner.

Johann Wolfgang Döbereiner was a German chemist who proposed the concept of triads to organize elements with similar properties into groups. In 1817, he observed that certain groups of three elements exhibited similar chemical properties and atomic masses. Döbereiner's work laid the foundation for the later development of the periodic table.

Döbereiner's triads consisted of three elements where the atomic mass of the middle element was approximately the average of the atomic masses of the other two elements. Additionally, the chemical properties of the middle element were often intermediate between those of the other two elements. One of the most well-known examples of Döbereiner's triads is the alkaline earth metals calcium (Ca), strontium (Sr), and barium (Ba), where the atomic mass of strontium falls approximately in the middle of the atomic masses of calcium and barium, and the chemical properties of strontium are similar to those of calcium and barium.

While Döbereiner's triads provided an initial attempt to organize the elements, they were limited in scope and could only accommodate a small number of elements. However, his work inspired later chemists to develop more comprehensive systems for organizing the elements, ultimately leading to the development of the modern periodic table by Dmitri Mendeleev and others in the late 19th century.