Describe Mendeleev's periodic table.

(N/A) Mendeleev's periodic law states that the physical and chemical properties of elements are a periodic function of their atomic weights.
Key features of Mendeleev's periodic table include:
$1$. Elements were arranged in order of increasing atomic weights.
$2$. It consisted of $8$ vertical columns called groups and $7$ horizontal rows called periods.
$3$. Mendeleev left gaps for elements that were yet to be discovered (e.g.,Eka-boron,Eka-aluminium,and Eka-silicon).
$4$. It allowed for the systematic study of elements and predicted the properties of unknown elements.