Question

2) (6h18min2isec) please answer =​

Answer 1

Answer:

what is it? pls say it properly

Answer 2

Answer:

Some gaps were left for the elements yet to be discovered. Thus, if a certain new element is discovered, it can be placed in a new group without disturbing any existing group. He was unable to locate hydrogen in the periodic table. Increase in atomic mass was not regular while moving from one element to another.