Question

Chlorine has two isotopes, viz. cl-35 and Cl-37. Their atomic masses are 35 and 37 respectively. Their chemical properties are same. where should these be placed in Mendeleev’s periodic table? In different places or in the same place?

Answer 1

The arrangement of elements is done on the basis of atomic mass. Since the atomic masses of chlorine (isotopes) are different i.e. 35 and 37, they should be kept in different places in Mendeleev’s periodic table.