Chapter 40, Problem 19A

To determine

The device used to measure the relative masses of ions of isotopes.

Explanation of Solution

Introduction:

The relative masses of the ions of the isotopes can be found by the atomic masses of the isotopes because the atomic mass of each isotope of an element always remains different.

The relative masses of the isotopes in a sample compared by the charge to mass ratio of the ion. The device in which the relative masses are found is called the mass spectrometer. The mass spectrometer uses a magnetic field to deflect the ions into circular arcs. The speed of all ions of isotope are same but their masses are different. The ion of heavier mass deflects less but lighter ion deflects more in the magnetic fields. The radius of curved path for heavier ion is less and more for lighter ion.

The relative masses of the ions of isotopes can be found by comparing the radius of curved path of ions in mass spectrometer.

Conclusion:

Thus, the mass spectrometer is used to measure the relative masses of ions of isotopes.