In a discharge tube ionization of enclosed gas is produced due to collisions between

Options

A. positive ions and neutral atoms/molecules
B. negative electrons and neutral atoms/molecules
C. photons and neutral atoms/molecules
D. neutral gas atoms/molecules

Answer

To solve the question regarding the ionization of gas in a discharge tube, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding the Discharge Tube**:
- A discharge tube consists of two electrodes: a cathode (negative electrode) and an anode (positive electrode). It is filled with a low-pressure gas.

2. **Applying a High Voltage**:
- When a high voltage is applied across the electrodes, it creates a potential difference that accelerates free electrons towards the anode and positive ions towards the cathode.

3. **Role of Free Electrons**:
- The free electrons, which are emitted from the cathode, gain kinetic energy as they move towards the anode.

4. **Collisions with Gas Atoms**:
- As these accelerated electrons travel through the gas, they collide with neutral gas atoms or molecules.

5. **Ionization Process**:
- During these collisions, if the energy of the electrons is sufficient, they can knock out one or more electrons from the gas atoms, resulting in the formation of positive ions and additional free electrons. This process is known as ionization.

6. **Resulting Ionization**:
- The newly freed electrons can then go on to cause further ionization by colliding with other neutral gas atoms, leading to a chain reaction of ionization.

7. **Conclusion**:
- Therefore, the ionization of the enclosed gas in a discharge tube is primarily produced due to collisions between the accelerated free electrons and the neutral gas atoms.

### Final Answer:
The ionization of enclosed gas in a discharge tube is produced due to collisions between **accelerated free electrons and neutral gas atoms**.

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