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Mendeleev’s classification

Dmitri Mendeleev (1869)

In 1869 Mendeleev and Lothar Meyer (Germany) published nearly identical classification schemes for elements known to date. The periodic table is base on the similarity of properties and reactivities exhibited by certain elements. Later, Henri Moseley ( England,1887-1915) established that each elements has a unique atomic number, which is how the current periodic table is organized

Features of Mendeleev’s periodic Table

Mendeleev arranged all the elements at that time (63 elements) in the increasing order of their atomic masses in such a way that chemically similar elements were placed in the same vertical column.

In Mendeleev’s periodic table, the elements were arranged in 7 horizontal rows (called periods) and eight vertical columns (called groups).

Mendeleev’s periodic law

Properties of elements depend on their atomic masses

When elements are arranged according to their atomic masses, properties are repeated at regular intervals.

Merits of Mendeleev’s Classification

Mendeleev’s left vacant spaces in the table, this stood for new elements yet to be discovered.

He corrected the atomic masses of certain elements.

He didn’t give proper place for hydrogen.He didn’t give proper place for transition

elements.He violate the increasing of atomic masses in

certain places.

Demerits of Mendeleev’s classification

Mendeleev’s periodic table