Question

Consider the following isotopes of chlorine:
${}_{17}C{l}^{35}{,}_{17}C{l}^{37}$,
Atomic masses of these isotopes are different, while their chemical properties are same. In the Mendeleev's periodic table isotopes of chlorine was placed:

• A. in the different groups
• B. in the same group
• C. in different periods
• D. both (A) and (C) are correct

Answer 1

The correct option is B in the same group

According to Mendeleev periodic properties of elements are functions of their atomic masses. Thus, isotopes should be place separately but as they are chemically similar they are placed in the same group.