Question

What is the wavelength of a photon with a frequency of 6.85 ✕ 1016 s-1?

Answer 1

$\lambda = \frac{c}{\nu}$

where $\lambda$ - wavelength of photon, $m$ ,

$c$ - speed of light, $c \approx 3 \cdot 10^{8} \; m \cdot s^{-1}$,

$\nu$ - frequency of photon, $s^{-1}$.

$\lambda = \frac{3 \cdot 10^{8}}{6.85 \cdot 10^{16}} \approx 4.38 \cdot 10^{-9} \; m = 4.38 \; nm$

Answer: 4.38 nm.