Mendeleev invented the Periodic Table in 1869.
In those days there were still elements missing, they had no idea of what electrons were or how they related to chemistry, or how the nucleus related to atomic weight.;
but they're really the same charts.
The modern periodic table was based on mendeleev's table however the modern one has the gaps filled (gallium, germanium and francium) that mendeleev left out as they had not yet been discovered.
the other change was to ignore the atomic weights rule and switch adjacent elements such as cobalt and nickel to better classify them into groups ( columns where valency is the same).
Hope that helps :)
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In Mendeleev's periodic table the elements were organised with increasing atomic weight whereas in the modern periodic table they are arranged with increasing atomic number.
There are more elements and it's organized differently
The modern long form of periodic table was constructed by Dmitri Mendeleev (1869).
Dmitri Mendeleev developed the modern periodic table in 1869.
I believe it was Dimitri Mendeleev. Alex was here
They have simliar properties and same elements although later on more elements were added to the modern periodic table.=Both periodic tables have elements grouped by similar properties. Mendeleev's periodic table had elements arranged in order of increasing atomic mass in columns with similar properties. While many of the elements are in order of atomic mass on the modern periodic table, some are not, as the modern table has elements arranged in order of increasing atomic number.=
There are more elements and it's organized differently
mendeleev
The modern long form of periodic table was constructed by Dmitri Mendeleev (1869).
Dmitri Mendeleev developed the modern periodic table in 1869.
Dmitri Mendeleev was a Russian chemist; he proposed the modern Periodic Table of elements in 1869.
Not all the elements were included
I believe it was Dimitri Mendeleev. Alex was here
Dimitri Mendeleev, a Russian chemist in 1869.
Dmitri Mendeleev came up with the modern Periodic Table in 1869.
Many more elements are known today then when Mendeleev laid out his table. In addition, he arranged his table by atomic mass and there are places in the periodic table where mass does not always increase. An example is between tellurium and iodine.
Mendeleev
This is the Russian chemist Dimitri Mendeleev.