Question

The whole number atomic mass of the elements cobalt (co) and nickel (ni) is the same therefore there was an ambiguity regarding their sequence in mendeleev's periodic table

Answer 1

Answer:

The elements cobalt(Co) and nickel(Ni) have the same whole number atomic mass. As a remit there was an ambiguity regarding theire sequence in Mendeleev's periodic table. ... It was not possible, therefore, to predict how many elements could be discovered between two heavy elements.