In Mendeleev's table, although most of the elements were placed in the order of increasing atomic masses, some pairs of the elements________were placed in the inverted order masses precede the elements with lower atomic mass.
(i) argon and postssium (ii) cobalt and nickel
(iii) tellurium and iodine

Options

A. `(i),(iii)`
B. `(i),(ii)`
C. `(ii),(iii)`
D. `(i),(ii),(iii)`

Answer

D

Explanation

The inversion of order in the periodic table was done due to the similarities in chemical properties of the element with the elements of that group in which it was placed. For example, tellurium was placed before iodine through it had a higher atomic mass because iodine had properties similar to those of bromine and not selenium.