Question

According to the law of triads :

• A. the properties of the middle element were in between those of the other two members.
• B. three elements arranged according to increasing weights have similar properties.
• C. the elements can be grouped in the groups of six elements.
• D. every third element resembles the first element in periodic table.

Answer 1

The correct option is A the properties of the middle element were in between those of the other two members.

According to Dobereiner's law of triads, the properties of the middle element were in between those of the other two members. The elements were arranged in a group of three (called triads). The atomic weight of a middle element was almost the average of the other two. Three elements of the triad had similar chemical properties.