Question

Differentiate between the properties of isotopes of chlorine.

Answer 1

Isotopes:

• The atoms of the same element having the same atomic number but different mass numbers are known as isotopes. i.e. same number of protons but different numbers of neutrons.
• The chemical properties of isotopes are similar as they have the same number of electrons and protons.
• Physical properties of isotopes like mass, melting point, boiling point, freezing point, density, etc. are different as they have different masses.

Isotopes of Chlorine $\mathbf{\left(}\mathbf{Cl}\mathbf{\right)}$:

Chlorine has two isotopes: $\mathrm{Cl}-35$ and $\mathrm{Cl}-37$.

• $\mathrm{Cl}-35$:

1. It contains $17$ protons and $18$ neutrons.
2. It is represented as ${}_{17}{}^{35}\mathrm{Cl}$.
3. Its relative abundance is $76\%$.

• $\mathrm{Cl}-37$:

1. It contains $17$ protons and $20$ neutrons.
2. It is represented as ${}_{17}{}^{37}\mathrm{Cl}$.
3. Its relative abundance is $24\%$

Differentiation between properties of isotopes of Chlorine:

1. The mass of $\mathrm{Cl}-35$ isotope is lower than that of $\mathrm{Cl}-37$.
2. Thus, the density of $\mathrm{Cl}-35$ isotope is less than that of $\mathrm{Cl}-37$.
3. Similarly, other properties like melting point, boiling point, and freezing point of $\mathrm{Cl}-35$ isotope are different than that of $\mathrm{Cl}-37$.