Thickness of the foil of gold used in `alpha`-particle scattering experiment is

Options

A. `2.1xx10^(-7)` m
B. `3.5xx10^(-5)` m
C. `2.1xx10^(-9)` m
D. `3.5xx10^(-6)` m

Answer

To find the thickness of the gold foil used in the alpha-particle scattering experiment, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Given Information:**
The thickness of the gold foil is given as 2100 angstroms.

2. **Convert Angstroms to Meters:**
We know that 1 angstrom (Å) is equal to \( 10^{-10} \) meters. Therefore, we need to convert 2100 angstroms to meters:
\[ \text{Thickness in meters} = 2100 \, \text{Å} \times 10^{-10} \, \text{m/Å} \]

3. **Perform the Calculation:**
\[ \text{Thickness in meters} = 2100 \times 10^{-10} \, \text{m} \]
This can be simplified:
\[ = 2.1 \times 10^{3} \times 10^{-10} \, \text{m} \]

4. **Combine the Powers of Ten:**
When multiplying powers of ten, we can add the exponents:
\[ = 2.1 \times 10^{-7} \, \text{m} \]

5. **Final Result:**
Thus, the thickness of the gold foil used in the alpha-particle scattering experiment is:
\[ t_0 = 2.1 \times 10^{-7} \, \text{meters} \]

### Conclusion:
The thickness of the gold foil is \( 2.1 \times 10^{-7} \, \text{m} \).