Question

The element ____ is in the Dobereiner triad Ca, ____ and Ba is
1. Be
2. Mg
3. Sr
4. I

Answer 1

Correct Answer - Option 3 : Sr

The correct answer is Sr.

• Dobereiner was a German scientist.
• He studied as a pharmacist at Munchberg (Germany).
• In 1829, he found some groups of three-element which showed similar properties. These groups were called triads.
• In these triads, the atomic mass of the middle element was approximately the mean of the atomic masses of the other two elements.
• The first three elements were Li, Na, K.
• He arranged the elements as per their atomic masses in increasing order.
• The second triad he found was Ca, Sr, Ba.