Question

when and by whom the periodic table was discovered???​

Answer 1

Mendeleeve. . . . . . . . . . . . . .

Answer 2

Answer:

In 1869 Russian chemist Dimitri Mendeleev started the development of the periodic table, arranging chemical elements by atomic mass. He predicted the discovery of other elements, and left spaces open in his periodic table for them.

Step-by-step explanation:

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