Gases begin to conduct electricity at low pressure because

Options

A. at low pressure gases trun to plasma
B. coliding electrons can acquired higher kinetic energy due to increased mean free path leading to ionisation of atoms
C. atoms break up into electronis and protons
D. the electrons in atoms can move freely at low pressure.

Answer

To solve the question "Gases begin to conduct electricity at low pressure because," we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding Conductivity in Gases**:
- Gases are generally poor conductors of electricity because their atoms or molecules are not ionized and are far apart from each other. At normal pressure, the density of gas is higher, and the free movement of charged particles is limited.

2. **Effect of Low Pressure**:
- When the pressure of a gas is reduced, the density of the gas decreases. This means that the gas molecules are farther apart, allowing for greater movement of particles.

3. **Ionization Process**:
- At low pressure, when a high voltage is applied, electrons can gain sufficient energy to ionize the gas molecules. This means that the electrons can knock out other electrons from the gas atoms, creating positive ions and free electrons.

4. **Formation of Plasma**:
- The process of ionization leads to the formation of plasma, which is a state of matter where electrons are separated from their nuclei. In this state, the gas can conduct electricity because there are free-moving charged particles (ions and electrons).

5. **Higher Kinetic Energy of Electrons**:
- The free electrons that are generated can acquire higher kinetic energy due to the electric field created by the high voltage. This increased kinetic energy allows them to collide with other gas molecules, causing further ionization and enhancing conductivity.

6. **Conclusion**:
- Therefore, gases begin to conduct electricity at low pressure because the reduced density allows for greater movement of electrons, leading to ionization and the formation of plasma, which can conduct electricity.

### Final Answer:
Gases begin to conduct electricity at low pressure because the lower density allows electrons to gain sufficient energy to ionize gas molecules, resulting in the formation of free electrons and ions that can move freely, thus enabling electrical conduction.

---