Question

Lithium, _____________ and potassium constitute a Dobereiner’s triad.choose the correct answer from the bracket.( Na,(sodium),atomic mass,18th,(8viiiₐ),7th period,metaalic)

Answer 1

sodium is in the dobereiner traid

Answer 2

Dear Student,

◆ Answer -

Lithium, sodium and potassium constitute a Dobereiner’s triad.

● Dobereiner's triads -

• Dobereiner paired elements in group of three such that atomic mass of middle element was the average of 1st & 3rd element.
• For example, mass of Na (A=23) is average of Li (A=7) and K (A=39).
• Other triads -

1. Ca, Sr & Ba
2. Cl, Br & I
3. S, Se & Te

Thanks dear. Hope this helps you...