Question

Notes on classification of elements and periodic table

Answer 1

in 1817 adjournment chemistry Jester a method of grouping the elements based on the relative atomic masses arrange the elements into groups containing three element is he called this group triadsshow that every element is arranged in ascending order of their atomic mass the atomic mass of the middle element is nearly the same as average out of atomic masses of other two elements that statement is called law of triads example Arithmetic mean of atomic masses of first and the elements




limitation


he could identify only 3 triadsfrom the elements known at that time and all elements could not be classified in the form of tree as the law was not applicable to Elements having very low atomic mass and very high atomic mass