Label the following statements about J. J. Thomson's cathode-ray tube experiments shown in Figure 2.6 as true or false. (f) By measuring the deflection of the cathode ray beam caused by electric fields of known strength, the charge-to-mass ratio of the electron was calculated.

Verified step by step guidance

1. Step 1: Understand the context of J.J. Thomson's cathode-ray tube experiments. Thomson used this experiment to discover the electron. He did this by applying electric and magnetic fields to a beam of particles (cathode rays) and observing their deflection.
2. Step 2: Recall that the deflection of the cathode ray beam in the presence of an electric field is due to the charge of the particles in the beam. The amount of deflection is related to the charge-to-mass ratio of the particles.
3. Step 3: Recognize that the statement is saying that the charge-to-mass ratio of the electron was calculated by measuring the deflection of the cathode ray beam caused by electric fields of known strength.
4. Step 4: Compare this statement with your understanding of Thomson's experiment. Thomson did indeed calculate the charge-to-mass ratio of the electron by observing the deflection of the cathode rays in the presence of electric fields.
5. Step 5: Therefore, the statement is true. Thomson's experiment allowed him to calculate the charge-to-mass ratio of the electron by observing the deflection of the cathode rays in the presence of electric fields.

Key Concepts

Cathode Ray Tube

A cathode ray tube (CRT) is a vacuum tube containing one or more electron guns and a phosphorescent screen, used to display images. In Thomson's experiments, the CRT was essential for studying the behavior of cathode rays, which are streams of electrons. The deflection of these rays in electric and magnetic fields provided insights into their properties, leading to the discovery of the electron.

Charge-to-Mass Ratio

The charge-to-mass ratio (e/m) of a particle is a fundamental property that describes how much electric charge a particle carries relative to its mass. In Thomson's experiments, he measured the deflection of cathode rays in electric fields to calculate this ratio for electrons. This measurement was crucial in establishing the electron as a subatomic particle with specific characteristics.

Deflection in Electric Fields

Deflection in electric fields occurs when charged particles, such as electrons, experience a force due to an electric field. The direction and magnitude of this deflection depend on the charge of the particle and the strength of the electric field. Thomson utilized this principle to determine the charge-to-mass ratio of electrons by observing how much the cathode rays were deflected when subjected to known electric fields.