To determine which type of radiation is represented by each numbered column in the table, we'll use the properties of different types of radiation and how they interact with various materials.
Here's the given table reformatted for clarity:
| Material | 1 | 2 | 3 |
|-----------------|-------|-------|-------|
| Lead | Stopped | Stopped | Stopped |
| Cloth | Not stopped | Stopped | Stopped |
| Aluminum foil | Not stopped | Stopped | Stopped |
| Wood | Not stopped | Stopped | Stopped |
| Paper | Not stopped | Stopped | Not stopped |
| Thick concrete | Stopped | Stopped | Stopped |
Let's analyze the columns:
1. Stopped by Lead, Concrete, but not by Cloth, Aluminum foil, Wood, or Paper
2. Stopped by Cloth, Aluminum foil, Wood, Paper, Lead, and Concrete
3. Stopped by Lead, Concrete, Cloth, Aluminum foil, Wood, but not by Paper
### Step-by-Step Identification:
1. Column 2 Analysis:
- This radiation type is stopped by almost all materials, including relatively thin ones like Paper.
- This suggests that Column 2 represents alpha particles, as alpha particles are heavy and are stopped even by a sheet of paper.
2. Column 1 Analysis:
- This type of radiation is not stopped by Paper but is stopped by thicker materials like Lead and Concrete.
- This suggests that Column 1 represents beta particles, which have a moderate penetrating power and can pass through paper but are stopped by denser materials.
3. Column 3 Analysis:
- This radiation type is only stopped by very thick materials like Lead and Concrete but not by thinner materials such as Paper, Cloth, Aluminum foil, or Wood.
- This pattern matches gamma rays, which are highly penetrating and require thick, dense materials to stop them.
From this analysis, we can conclude the following:
- [tex]\(1 = \text{beta}\)[/tex]
- [tex]\(2 = \text{alpha}\)[/tex]
- [tex]\(3 = \text{gamma}\)[/tex]
So, the correct mapping of the numbered spots in the table is:
[tex]\[ 1 = \text{beta}; \, 2 = \text{alpha}; \, 3 = \text{gamma} \][/tex]
And the corresponding multiple-choice option is:
[tex]\[
\boxed{1 = \text{beta}; \, 2 = \text{alpha}; \, 3 = \text{gamma}}
\][/tex]
