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

Answer: (A)

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.