Atomic Structure and Chemical Bonding — Question 29

Isotopes have the same atomic number i.e., the same number of electrons and protons and hence the same electronic configuration. Chemical properties are determined by the electronic configuration of an atom. Thus, the isotopes of an element are chemically alike.

Isotopes have different mass numbers [A] due to different number of neutrons. ³⁵₁₇Cl has 18 neutrons whereas ³⁷₁₇Cl has 20 neutrons. Due to different atomic masses these atoms differ in their physical properties like density, melting point, boiling point, etc.