Question

why did mendeleeves left spaces in his periodic table​

Answer 1

Answer:

Because the properties repeated themselves regularly, or periodically, on his chart, the system became known as the periodic table. In devising his table, Mendeleev did not conform completely to the order of atomic mass. ... He left blank spaces in his chart as placeholders to represent those unknown elements.

Answer 2

Because the properties repeated themselves regularly, or periodically, on his chart, the system became known as the periodic table. In devising his table, Mendeleev did not conform completely to the order of atomic mass. ... He left blank spaces in his chart as placeholders to represent those unknown elements.