Charge to mass ratio of electron was determined by

Options

A. James Chadwick
B. J.J. Thomson
C. Goldstein
D. Ernest Rutherford

Answer

To determine the charge to mass ratio of the electron, we can follow these steps:

### Step 1: Understand the Concept
The charge to mass ratio (e/m) of an electron is defined as the ratio of the charge of the electron to its mass. This ratio is crucial in understanding the behavior of electrons in electric and magnetic fields.

### Step 2: Identify the Charge and Mass of the Electron
The charge of an electron (e) is approximately \(1.6 \times 10^{-19}\) coulombs, and the mass of an electron (m) is approximately \(9.1 \times 10^{-31}\) kg.

### Step 3: Calculate the Charge to Mass Ratio
Using the values of charge and mass:
\[ \frac{e}{m} = \frac{1.6 \times 10^{-19} \text{ C}}{9.1 \times 10^{-31} \text{ kg}} \]

### Step 4: Perform the Calculation
Calculating the above expression:
\[ \frac{e}{m} \approx 1.76 \times 10^{11} \text{ C/kg} \]

### Step 5: Historical Context
The charge to mass ratio of the electron was first determined by J.J. Thomson in 1897 through his experiments with cathode rays. His work provided foundational evidence for the existence of electrons.

### Conclusion
Thus, the charge to mass ratio of the electron was determined by J.J. Thomson.

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