The most penetrating radiation out of the following is

Options

A. `gamma`-rays
B. `alpha`-particles
C. `beta`-rays
D. `X`-rays

Answer

To determine the most penetrating radiation among the given options (gamma rays, alpha particles, beta rays, and x-rays), we can analyze the properties of each type of radiation.

### Step-by-Step Solution:

1. **Identify the Types of Radiation**:
- The options given are:
- A) Gamma rays
- B) Alpha particles
- C) Beta rays
- D) X-rays

2. **Understand the Nature of Each Radiation**:
- **Alpha Particles**: These are heavy, positively charged particles consisting of 2 protons and 2 neutrons. They have low penetrating power and can be stopped by a sheet of paper or the outer layer of skin.
- **Beta Rays**: These are electrons or positrons emitted from a nucleus. They have a greater penetrating ability than alpha particles but can be stopped by a few millimeters of plastic or a thin sheet of metal.
- **X-rays**: These are high-energy electromagnetic waves. They have better penetrating power than alpha and beta particles and can pass through soft tissues but are absorbed by denser materials like bone.
- **Gamma Rays**: These are high-energy electromagnetic radiation with very short wavelengths. They have the highest penetrating power among all types of radiation and can pass through most materials, requiring dense materials like lead or several centimeters of concrete to be effectively shielded.

3. **Compare the Penetrating Powers**:
- Based on the above understanding:
- Alpha particles have the least penetrating power.
- Beta rays have moderate penetrating power.
- X-rays have higher penetrating power than beta rays.
- Gamma rays have the highest penetrating power of all.

4. **Conclusion**:
- From the analysis, we conclude that the most penetrating radiation among the given options is **gamma rays**.

Thus, the correct answer is **A) Gamma rays**.