Question

Mendeleev periodic table is based on
A. Atomic number
B. Increasing order of number of protons
C. Electronic configuration
D. None of the above.

Answer 1

Elements are arranged in a tabular form called periodic table and there are 115 elements present in the periodic table. There are similarities as well as differences in the properties of these elements. On the basis of these properties elements can be divided into metals and non-metals.

Complete answer:
Modern periodic table given by Mandeleev consists of 18 vertical columns known as groups arranged as left to right and seven horizontal rows known as periods arranged from top to bottom. In this periodic table elements are arranged according to their atomic number and this table divides the elements into s, p, d and f-block elements on the basis of their valence shell electrons.
The order of atomic size can be explained on the basis of periodic table where periodic table is the table in which all elements are placed according to their atomic number and their reoccurrence properties and atomic size decreases as we move from left to right in the periodic table this can be explained on the basis of effective nuclear charge and atomic size increases as we move down the group this is due to the increase in the number of shells.

Hence option A is the correct answer.

Note:
Atomic size is defined as the distance between the center of nucleus of an atom and its outermost shell. Where an atom consists of a nucleus which is made up of protons and neutrons and electrons are revolving around the nucleus.