In Mendeleev's period table, the elements were arranged by both weight and valence. Mendeleev noticed certain elements were very close in weight and properties and hypothesized other elements that would lie between them. These were the basis of groups. He also noticed weights increased regularly and formed these into periods.
it has elements
Chemists....
Mendeleev predicted that properties of elements are periodic function of atomic mass. He demonstrated it by creating a table.
Periodic table help to estimate the chemical and physical properties of elements.
as a reference tool
it has elements
To understand the concept of Periodic Table
They used atomic number instead of Atomic Mass to organize the elements
Chemists....
Mendeleev's periodic table of elements certainly wasn't created in 1901
In Mendeleev's periodic table, the elements were arranged in the increasing order of their atomic masses and repeating periodic properties.
Chemists
Periodic table group elements with similar properties together. It makes study of elements easier for chemists.
How have chemists used the Periodic Table over time
Mendeleev predicted that properties of elements are periodic function of atomic mass. He demonstrated it by creating a table.
By grouping the elements on the Periodic Table.
as a reference tool