The frequency of light for 1.0 `Å` wavelenght is :-

Options

A. `3xx10^(18)Hz`
B. `3xx10^(18)sec^(-1)`
C. `3xx10^(18)` Cycles per sec
D. All of the above.

Answer

To find the frequency of light for a wavelength of 1.0 Å (angstrom), we can follow these steps:

### Step 1: Convert Wavelength to Meters
The given wavelength is 1.0 Å. We need to convert this into meters for our calculations.
1 Å = \(10^{-10}\) meters.
So,
\[ \lambda = 1.0 \, \text{Å} = 1.0 \times 10^{-10} \, \text{m} \]

### Step 2: Use the Speed of Light Formula
The speed of light (c) is given by the equation:
\[ c = \nu \times \lambda \]
where:
- \(c\) is the speed of light, approximately \(3 \times 10^8 \, \text{m/s}\),
- \(\nu\) is the frequency,
- \(\lambda\) is the wavelength.

### Step 3: Rearrange the Formula to Solve for Frequency
We need to find the frequency (\(\nu\)), so we rearrange the formula:
\[ \nu = \frac{c}{\lambda} \]

### Step 4: Substitute the Values
Now we can substitute the values into the equation:
\[ \nu = \frac{3 \times 10^8 \, \text{m/s}}{1.0 \times 10^{-10} \, \text{m}} \]

### Step 5: Perform the Calculation
Calculating the above expression:
\[ \nu = 3 \times 10^8 \div 1.0 \times 10^{-10} = 3 \times 10^{18} \, \text{s}^{-1} \]

### Step 6: Express the Frequency
The frequency can also be expressed in hertz (Hz) or cycles per second:
\[ \nu = 3 \times 10^{18} \, \text{Hz} \]

### Conclusion
Thus, the frequency of light for a wavelength of 1.0 Å is:
\[ \nu = 3 \times 10^{18} \, \text{Hz} \]