Understanding the Relationship

* Speed of light (c): This is a constant, approximately 3 x 10⁸ meters per second (m/s).

* Wavelength (λ): The distance between two successive crests or troughs of a wave (given as 4000 angstroms).

* Frequency (f): The number of waves passing a point per second.

Formula:

The relationship between these three is:

c = fλ

Conversion:

* Angstroms to meters: 1 angstrom (Å) = 1 x 10^-10 meters

Calculation:

1. Convert wavelength to meters: 4000 Å * (1 x 10^-10 m/Å) = 4 x 10^-7 m

2. Rearrange the formula to solve for frequency: f = c/λ

3. Plug in the values: f = (3 x 10⁸ m/s) / (4 x 10^-7 m)

4. Calculate: f = 7.5 x 10¹⁴ Hz

Answer: The frequency of blue light with a wavelength of 4000 angstroms is 7.5 x 10¹⁴ Hertz (Hz).