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 need to analyze the characteristics of each type of radiation and their respective penetrating abilities.

### Step-by-Step Solution:

1. **Identify the Types of Particles**:
- **Alpha Particles**: These are helium nuclei consisting of 2 protons and 2 neutrons. They are positively charged and relatively heavy.
- **Beta Particles**: These are high-energy, high-speed electrons (or positrons) emitted from a nucleus during radioactive decay. They have a small mass compared to alpha particles.
- **Gamma Rays**: These are electromagnetic radiation (photons) with no mass and travel at the speed of light. They carry energy but do not have charge or mass.

2. **Understanding Penetrating Power**:
- The penetrating power of a particle is influenced by its mass and charge. Generally, the greater the mass and charge of a particle, the less penetrating power it has.
- **Alpha particles**, being the heaviest and positively charged, have the least penetrating power. They can be stopped by a sheet of paper or even the outer layer of human skin.
- **Beta particles**, being lighter and negatively charged, have more penetrating power than alpha particles. They can penetrate through paper but are stopped by a few millimeters of plastic or glass.
- **Gamma rays**, being massless and uncharged, have the highest penetrating power. They can penetrate through several centimeters of lead or several meters of concrete.

3. **Conclusion**:
- Based on the above analysis, we can conclude that the statement "Alpha particles have maximum penetrating power" is **false**. The correct order of penetrating power from highest to lowest is: **Gamma rays > Beta particles > Alpha particles**.

### Final Answer:
The statement is **false**. Gamma rays have the maximum penetrating power, followed by beta particles, and then alpha particles.

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