What is the basic difference in approach between the Mendeleev's Periodic Law and the Modern Periodic Law?

State whether the following statements are true or false:
$(i)$ The chart of elements presented by $Courtois$ could predict the stoichiometry of oxides of some metals.
$(ii)$ $Li, Na, Rb$ are known as $Döbereiner's$ triads.
$(iii)$ In $1863$,$Newlands$ classified the $56$ discovered elements into $18$ groups.
$(iv)$ $Mendeleev's$ periodic table is based on the atomic number of elements.

On the basis of which property did Mendeleev arrange the elements?

The law of triads is applicable to a group of

Given below are two statements :
Statement $(I):$ According to the Law of Octaves,the elements were arranged in the increasing order of their atomic number.
Statement $(II) :$ Meyer observed a periodically repeated pattern upon plotting physical properties of certain elements against their respective atomic numbers.
In the light of the above statements,choose the correct answer from the options given below :

Who stated that the properties of elements are a periodic function of their atomic number?