(a) State Newland Law of Octaves. (b) With an example, explain Dobereiner's Triads. (c) List one limitation…
(a) State Newland Law of Octaves.
(b) With an example, explain Dobereiner's Triads.
(c) List one limitation each of both the attempts mentioned in 'a' & 'b'.
Solution
(a) "When the elements are arranged in the order of their increasing atomic masses, then every eighth element has properties similar to the first element."
(b) When the elements of a triad are arranged in the order of their increasing atomic masses, the atomic mass of the middle element is equal to the average of the atomic masses of other two elements.
Examples:
Li Na K
Ca Sr Ba
Cl Br I
(Any one example)
(c) Limitations of :-
Newlands' Law : Applicable till Calcium / assumed that only 56 elements existed / unlike elements placed in the same column (Co, Ni).
Dobereiner's Triads : Only three triads were formed.