Question

Why do the isotopes of same elements have similar chemical properties?

Answer 1

• Isotopes- Atoms of an element having the same atomic number but a different mass number are known as isotopes.
• Atomic number (Z)- The total number of protons in the nucleus of an atom gives us the atomic number of that atom.
• Mass number (A)- The number of protons and neutrons combine to give us the mass number of an atom.
• Let us take an example of two isotopes of Chlorine(Cl) ${{}^{35}\mathrm{Cl}}_{17}$ and ${{}^{37}\mathrm{Cl}}_{17}$-

Isotope	Number of electrons	Number of protons	Number of neutrons
${{}^{35}\mathrm{Cl}}_{17}$	17	17	18
${{}^{37}\mathrm{Cl}}_{17}$	17	17	20

• Here it is evident that the number of electrons is the same in both atoms.
• The chemical properties of an element are dependent on the number of electrons.

Since both isotopes have the same number of electrons. So, they have the same chemical properties.