Final answer:
To find the frequency of a photon, you use the equation f = c / λ. Using the provided wavelength of 4.2 x 10^-7 m and the speed of light (3 x 10^8 m/s), the calculated frequency is 7.14 x 10^14 Hz, which does not match the options given.
Step-by-step explanation:
The question is asking to calculate the frequency of a photon with a given wavelength. The equation that relates the speed of light (c), wavelength (λ), and frequency (f) is c = λ × f. To solve for frequency, we rearrange the equation as f = c / λ. Given that the speed of light is 3 × 108 m/s and the wavelength provided is 4.2 × 10-7 m (conversion from millimeters to meters), we can calculate the frequency:
f = (3 × 108 m/s) / (4.2 × 10-7 m)
f = 7.14 × 1014 Hz
However, this value does not match any of the options provided. There might be an error in the question or units may have been misinterpreted. Please double-check the wavelength and units provided.