Question

How many elements were known when mendeleev gave his periodic table ? ​

Answer 1

$\huge \mathfrak \red{⚛63⚛}$

Answer 2

Answer

63 elements

Explanation

To put some order into his study of chemical elements, Mendeleev made up a set of cards, one for each of the 63 elements known at the time. Mendeleev wrote the atomic weight and the properties of each element on a card.