Arnongst a,`beta`,`gamma`.7.rays, a particle has maximum penetrating power.

Answer

To solve the question regarding the penetrating power of alpha, beta, and gamma rays, we will analyze the properties of each type of radiation step by step.

### Step-by-Step Solution:

1. **Understanding the Types of Radiation**:
- **Alpha Particles**: These are helium nuclei consisting of 2 protons and 2 neutrons. They are relatively large and carry a +2 charge.
- **Beta Particles**: These are high-energy, high-speed electrons (or positrons) emitted from a nucleus during radioactive decay. They are much smaller than alpha particles and carry a -1 charge (for electrons).
- **Gamma Rays**: These are electromagnetic waves (photons) with no mass or charge. They travel at the speed of light.

2. **Comparing Sizes**:
- Alpha particles are the largest in size, followed by beta particles, and then gamma rays, which are massless and chargeless.

3. **Penetrating Power**:
- The penetrating power of a particle is determined by its mass and charge. Heavier and charged particles (like alpha particles) interact more with matter and are less penetrating.
- Alpha particles have low penetrating power and can be stopped by a sheet of paper or a few centimeters of air.
- Beta particles have moderate penetrating power and can penetrate paper but are stopped by a few millimeters of aluminum.
- Gamma rays, being massless and uncharged, have the highest penetrating power and can pass through several centimeters of lead or meters of concrete.

4. **Conclusion**:
- Based on the properties discussed, the order of penetrating power from highest to lowest is: **Gamma rays > Beta particles > Alpha particles**.
- Therefore, the statement "Alpha particle has maximum penetrating power" is **false**.

### Final Answer:
The statement is **false**. Gamma rays have the maximum penetrating power among alpha, beta, and gamma rays.

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