What is the energy of a photon of light having a wavelength of 4.5 x 10-7 meters? (Planck’s constant is 6.626 x 10-34 joule seconds; the speed of light is 2.998 x 108 m/s)

Question

michele_laino · Answer

hint:
the requested energy is given by the subsequent formula:
$$\Large \begin{gathered}
  E = h\nu  = \frac{{hc}}{\lambda } =  \hfill \
   \hfill \
   = \frac{{6.62 \cdot {{10}^{ - 34}} \times 3 \cdot {{10}^8}}}{{4.5 \cdot {{10}^{ - 7}}}} = ...joules \hfill \ 
\end{gathered} $$