Question

How many elements were known when mendeleev started his work on his periodic table?

Answer 1

Answer:

During Mendeleev's work, only 63 elements were known. After studying the properties of every element, Mendeleev found that the properties of elements were related to atomic mass in a periodic way.

Answer 2

Explanation:

$\huge\mathfrak\purple{Hello\: Mate}$

$<font color=red> During Mendeleeves work, only 63 elements were known </font>$