Dmitri Mendeleev.
It was discovered in December 1949, so probably shortly after that.
The periodic table is an orderly arrangement of elements based on their atomic number, electron configuration, and chemical properties. It organizes elements into groups and periods to show trends in their behavior and properties.
glenn seaborg
Ununoctium was discovered (prepared) in 2006; old Mendeleev tables (printed before 2006) don't contain ununoctium.
Dmitri Mendeleev was the Russian scientist who discovered the periodic law and created the first version of the periodic table in 1869. He arranged the known elements by their atomic mass, demonstrating a periodic arrangement of properties that revealed recurring patterns.
The periodic table is an arrangement of the elements by atomic number. It was made by Dmitri (Deh-Mee-Tri) Mendeleev (Men-Del-Leh-Av) The set-up and the specific details vary due to the different types of tables.
Pythagora discovered time tables
Hydrogen.
Go to this website
Moseley discovered the modern periodic table.
I accidentally the answer.
The answer isDesign