MCQ Detailed View

The mass spectrograph is a scientific instrument that separates atoms and molecules based on their mass-to-charge ratio (m/z). It was invented by the British physicist Francis William Aston (F. W. Aston) in 1919. This was a landmark achievement in modern physics and chemistry because it allowed scientists to study isotopes in detail and measure their masses with great accuracy.

F. W. Aston used his mass spectrograph to show that many elements are made up of isotopes. Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons, which gives them different atomic masses. For example, chlorine exists mainly as two isotopes: chlorine-35 and chlorine-37. Aston’s invention proved the existence of isotopes beyond doubt and helped explain why atomic weights are not always whole numbers.

The principle of the mass spectrograph is simple but powerful. Charged particles (ions) are accelerated through an electric field and then passed through a magnetic field. Because ions with different masses are deflected by different amounts, they can be separated and detected. This technique is still the foundation of modern mass spectrometry, which is widely used today in chemistry, biology, medicine, and environmental science to identify compounds, analyze mixtures, and even study DNA.

For his discovery of isotopes and invention of the mass spectrograph, F. W. Aston was awarded the Nobel Prize in Chemistry in 1922. His work revolutionized atomic science and gave scientists one of the most accurate tools to measure atomic and molecular masses.

In short, the invention of the mass spectrograph by F. W. Aston opened the door to isotope research, improved the atomic mass scale, and laid the foundation for countless modern scientific techniques.