To determine the type of radiation emitted by Source 2, we need to analyze how the Geiger readings change with the introduction of different types of screens (paper and aluminium). The readings given for Source 2 are as follows:
- Without any screen: 98 counts per minute
- With a sheet of paper: 95 counts per minute
- With a sheet of aluminium: 5 counts per minute
Let's step through the analysis based on these observations:
1. Initial Reading Without Screens:
- The initial reading without any screen is 98 counts per minute.
2. Effect of Paper Screen:
- When a sheet of paper is used to screen the Geiger counter, the reading slightly decreases to 95 counts per minute.
- This slight reduction indicates that the paper is able to block or absorb only a small amount of the radiation. Since paper is known to effectively block alpha particles, the minor change suggests that the radiation is not primarily composed of alpha particles.
3. Effect of Aluminium Screen:
- When a sheet of aluminium is used to screen the Geiger counter, the reading significantly decreases to 5 counts per minute.
- Aluminium is effective in blocking beta particles. The significant reduction from 95 to 5 counts per minute when using aluminium suggests that the radiation is greatly affected by the aluminium screen.
Based on these observations:
- The radiation from Source 2 is slightly reduced by a paper screen but significantly reduced by an aluminium screen.
- This pattern of reduction is characteristic of beta radiation, which can penetrate paper to some extent but is largely stopped by aluminium.
Conclusion:
The type of radiation emitted by Source 2 is beta radiation.
