Question

Chlorine has two isotopes, viz, C1-35 and C1-37. 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

Atomic mass is used to order the elements. Since the isotopes of chlorine have different atomic masses, 35 and 37, they need to be stored separately in Mendeleev's periodic table.