Chapter 31, Problem 1CQ

Suppose the range for 5.0 MeVa ray is known to be 2.0 mm in a certain material. Does this mean that every 5.0 MeVa a ray that strikes this material travels 2.0 mm, or does the range have an average value with some statistical fluctuations in the distances traveled? Explain.

To determine

Whether it means that every $5.0\text{ MeV}$ $\alpha$ray that strikes this material travels $2.0\text{mm}$ , or the range have an average value with some statistical fluctuations in the distances traveled, suppose the range for $5.0\text{ MeV}$ $\alpha$ ray is known to be $2.0\text{mm}$ in a certain material

Answer to Problem 1CQ

Every 5.0 MeVa a ray that strikes this material won't travel 2.0 mm.

Explanation of Solution

Concept Used:

Nuclear radioactivity.

The distance travel by the radiation through a material is defined as the range of the radiation. The range of radiation depends upon some of the factors which includes the energy of the radiation, the material through which it travels and the type of the radiation whether alpha, beta or gamma ray. By defining these factors or by knowing these factors we can know the range of the radiation. Here it is given that range of radiation is 2 mm for a certain material, But the charged particles in the material interacts with rays and because of that ray will show some random fluctuations, so every $5.0\text{ MeV}$ $\alpha$ray won't travel $2.0\text{mm}$ on the same material. In the $\alpha$ decay the energy released in it is about $\text{MeV}$ range. It is about ${10}^6$ for a typical chemical reaction. Most of the energy is converted in kinetic energy of the $\alpha$ particle which moves at high speed

Conclusion:

Thus, every 5.0 MeVa a ray that strikes this material won't travel 2.0 mm.