Which of the following statements about the electron is incorrect?

Options

A. It is a negatively charged particle.
B. The mass of electron is equal to the mass of neutron.
C. It is a basic constituent of all atoms.
D. It is a constituent of cathode rays.

Answer

To determine which statement about the electron is incorrect, let's analyze each of the four statements provided:

1. **Statement 1**: "It is negatively charged particles."
- **Analysis**: Electrons are indeed negatively charged particles. This statement is correct.

2. **Statement 2**: "The mass of electron is equal to the mass of neutron."
- **Analysis**: The mass of an electron is approximately \(9.1 \times 10^{-31}\) kg, while the mass of a neutron is approximately \(1.67 \times 10^{-27}\) kg. The mass of a neutron is significantly greater than that of an electron. Therefore, this statement is incorrect.

3. **Statement 3**: "It is a basic constituent of all atoms."
- **Analysis**: Electrons are fundamental components of atoms, along with protons and neutrons. This statement is correct.

4. **Statement 4**: "It is a constituent of cathode rays."
- **Analysis**: Cathode rays are indeed streams of electrons emitted from the cathode in a vacuum tube. This statement is also correct.

After evaluating all the statements, we find that the incorrect statement is:

**Conclusion**: The incorrect statement about the electron is **Statement 2**: "The mass of electron is equal to the mass of neutron."