What are the characteristics of mendeleev's periodic table?

Mendeleev claimed the famous periodic law that “Element properties are a periodic function of their atomic weight.” Mendeleev placed elements in the order of their atomic weights in the form of a table known as the Periodic Table of Mendeleev.

Characteristics of Mendeleev’s periodic table:

1. In Mendeleev periodic table, vertical columns in the periodic table and horizontal row in the periodic table were named as groups and period respectively.
2. The periodic table is composed of seven horizontal rows or periods and is numbered between 1 to 7.
3. There is a regular gradation in the properties of elements in the horizontal rows(periods) from left to right.
4. The periodic table is composed of eight vertical columns or groups. They are numbered between 1 to 8.
5. If the element is similar but not much, to distinguish between them, it is placed below and slightly away from it. Thus, each column will have two sub-columns A and B, so elements will show more similarity in the same sub-columns.
6. Groups from I to VII are meant for normal elements and group VIII is for transition elements.
   Groups from I to VII have been divided into two subgroups, while group VIII is meant for three elements.
7. Periods from 4th to 7th have been divided in two series: 1st series and 2nd series.
8. Elements having similar properties have been kept in the same group. For example; lithium, potassium, rubidium, etc. are in 1st group.
9. Two general formulae; one for oxides and second for hydrides; have been given for the elements of each group in the periodic table. For example: R2O for oxides and RH for hydrides, of the elements; of 1st group.
10. Using the given general formulae; the formula of oxides and hydrides can be written for the elements of each group. For example; hydrogen, sodium, potassium, etc. belong to the first group. The general formula of oxides for the elements of 1st group is R2O. Accordingly they form H2O, Na2O, K2O, etc