Historical Figures

What did Dmitri periodic table look like?

Dmitri Mendeleev's First Periodic Table (1869)

Mendeleev's first periodic table, published in 1869, was a simple table with 17 columns, corresponding to the number of known elements at the time. The elements were arranged in rows based on their atomic masses, and the table showed clear patterns of periodicity in their properties.

The table was divided into four horizontal rows, called periods, and seven vertical columns, called groups. The periods were numbered 1 through 4 from top to bottom, and the groups were numbered 1 through 7 from left to right.

The first period contained only two elements, hydrogen and helium. The second period contained eight elements, from lithium to fluorine. The third period contained eight elements, from sodium to chlorine. And the fourth period contained eight elements, from potassium to bromine.

The groups were arranged based on the elements' chemical properties. For example, all of the elements in Group 1 were highly reactive metals, and all of the elements in Group 7 were non-reactive gases.

Mendeleev's periodic table was a major breakthrough in chemistry, and it has since been expanded and refined to include all of the known elements. The periodic table is a fundamental tool for understanding the properties and behavior of elements, and it is used by chemists and scientists around the world.

Here is a diagram of Mendeleev's first periodic table:

[Image of Mendeleev's first periodic table]

Key features of Mendeleev's first periodic table:

* The elements are arranged in rows (periods) and columns (groups) based on their atomic masses and chemical properties.

* The table is divided into four periods (1 through 4) and seven groups (1 through 7).

* The first period contains only two elements, hydrogen and helium.

* The second, third, and fourth periods each contain eight elements.

* The groups are arranged based on the elements' chemical properties.

* Mendeleev's periodic table was a major breakthrough in chemistry, and it has since been expanded and refined to include all of the known elements.