Question

history of periodic tablem...........pic ​

Answer 1

Answer:

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. In 1886 French physicist Antoine Bequerel first discovered radioactivity.

Explanation:

>>>In 1680 Robert Boyle also discovered phosphorus, and it became public.

>>>>>In 1809 at least 47 elements were discovered, and scientists began to see patterns in the characteristics.

>>>>In 1863 English chemist John Newlands divided the then discovered 56 elements into 11 groups, based on characteristics.

Answer 2

In 1869 Russian chemist Dmitri Mendeleev started the development of the periodic table, arranging chemical element according to their atomic mass.