Question

“The three elements were written in the order of increasing atomic mass the
atomic mass of middle element was roughly the average of the atomic masses
of other two elements.” This law was stated by
B. Mendeleev
A. Dobereiner
D. Newlands
C. Henry Moseley​

Answer 1

Answer:

Dobereiner

Explanation:

Answer is in Dobereiners law of triads.

Take the triad consisting of lithium (Li), sodium (Na)

and potassium (K) with the respective atomic masses 6.9, 23.0 and 39.0. You find that mass of Na is equal to the mass of average of Li and K