Question

According to Mendeleev's ′ Periodic Law, the elements were arranged in the periodic table in the order of 

(a) increasing atomic number 

(b) decreasing atomic number 

(c) increasing atomic masses 

(d) decreasing atomic masses

Answer 1

The answer is (c) increasing atomic masses

In 1869, Dmitri Mendeleev and Lothar Meyer individually came up with their own periodic law "when the elements are arranged in order of increasing atomic mass, certain sets of properties recur periodically."