Which of the following sets of elements correctly represent Dobereiner's triads based on their prope — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

Dobereiner's triads are groups of three elements with similar chemical properties where the atomic mass of the middle element is roughly the average of the other two. Valid triads include ($Li, Na, K$), ($Ca, Sr, Ba$), ($Cl, Br, I$), ($S, Se, Te$), and ($P, As, Sb$). The set ($Mg, Ca, Sr$) is not a valid triad because the average mass of $Mg$ and $Sr$ does not approximate $Ca$.