Question

According to Lothar Meyer, how should we arrange the elements in the increasing order?

Answer 1

Hint: Lothar Meyer gave a concept of a periodic table which comprises 28 elements organised according to their valency. The elements were almost entirely belonging to main group elements but later, he incorporated the concept of transition metals in a much more developed table.

Complete answer:
Lothar Meyer was a German chemist and was one of the pioneers in developing the earliest versions of the periodic table by arranging chemical elements according to a specific order. According to Lothar Meyer, if the elements in the periodic table were arranged in increasing order of their atomic masses, then they can be categorized into groups having similar chemical and physical properties which repeat at certain periodic intervals.
Lother Meyer plotted various physical properties of chemical elements like atomic volume versus atomic weight and obtained different curves. From these curves, he observed that elements which have similar physical properties occupy a similar position in the curve.

The two reasons for which Lothar Meyer’s periodic classification of elements was not much appreciated are as follows:
1. The periodic table given by Lothar Meyer was incomplete as compared to Mendeleev’s periodic table which was published in the same year with remarkable predictions of various elements.
2. There was no empirical or logical basis of classification in Lothar Meyer’s periodic table. It was only supported by facts of various physical properties like atomic volume, brittleness and electrochemical behaviour related to atomic masses.
Therefore, we can conclude that according to Lothar Meyer, the elements should be arranged in the increasing order of their atomic masses.

Note:
A noteworthy point here is that Meyer also included the predictions of future elements in his periodic table like Mendeleev, but he didn’t emphasize these predictions and also did not suggest any details of the physical and chemical properties of the future elements. Thus, Mendeleev’s periodic table is comparatively better than Luther Meyer’s periodic classification.