In an atom the ratio of radius of orbit of electron to the radius of nucleus is

Options

A. `10^3`
B. `10^4`
C. `10^5`
D. `10^6`

Explanation

To find the ratio of the radius of the orbit of an electron to the radius of the nucleus in an atom, we can follow these steps:

### Step 1: Identify the radius of the electron orbit
The radius of the electron orbit is typically given as:
\[ r_e = 10^{-10} \, \text{m} \]

### Step 2: Identify the radius of the nucleus
The radius of the nucleus is usually given as:
\[ r_n = 10^{-15} \, \text{m} \]

### Step 3: Set up the ratio
We need to find the ratio of the radius of the electron orbit to the radius of the nucleus:
\[ \text{Ratio} = \frac{r_e}{r_n} \]

### Step 4: Substitute the values into the ratio
Now, substituting the values we identified:
\[ \text{Ratio} = \frac{10^{-10}}{10^{-15}} \]

### Step 5: Simplify the ratio
To simplify this expression, we can use the properties of exponents:
\[ \text{Ratio} = 10^{-10 - (-15)} = 10^{-10 + 15} = 10^{5} \]

### Step 6: Conclusion
Thus, the ratio of the radius of the orbit of an electron to the radius of the nucleus is:
\[ \text{Ratio} = 10^{5} \]

### Final Answer
The ratio of the radius of the orbit of an electron to the radius of the nucleus is \( 10^{5} \).

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