How many triads were mentioned in Dobereiner's Triads?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. Four.
Dobereiner identified four triads. These triads were groups of three elements with similar chemical properties. The atomic weight of the middle element in each triad was approximately the average of the atomic weights of the other two elements.
Here are the four triads identified by Dobereiner:
- Chlorine, Bromine, Iodine
- Calcium, Strontium, Barium
- Sulfur, Selenium, Tellurium
- Lithium, Sodium, Potassium
However, this classification system had limitations as it could not accommodate all known elements.