Chapter 25, Problem 77A

Interpretation Introduction

Interpretation:

It is to be explained why alpha particles are less penetrating.

Concept introduction:

An unstable atomic nucleus loses energy via radiation through radioactive decay. A material is deemed radioactive if its nuclei are unstable.

Answer to Problem 77A

Alpha particles are slow, heavy, and attracted to opposite-charged particles.

Explanation of Solution

An helium atom’s nucleus and an alpha particle have many similarities (mass of $4$ and positive charge of $2$ ). Alpha particles are heavy, slow, and slow because of their huge mass. They also attract particles with the opposite charge because of their positive charge. Alpha particles have little penetration power as a result.

They only move in the air for approximately an inch and are relatively heavy. When their source is outside the human body, alpha particles pose no threat because they can be easily covered by a single sheet of paper and cannot pass through the outer, dead layer of skin.

Alpha particles are slow, heavy, and attracted to opposite-charged particles.

Conclusion

• Alpha particles are slow, heavy, and attracted to opposite-charged particles.
• Alpha particles have little penetration power as a result.