Calculate the energy for 1 mol of photons (an einstein) for light absorbed at 695 nm.

Answer 1

E = hc / λ

E = energy = ?

h = Planck's constatn = 6/626x10^-34 J-s

c = speed of llight = 3x10⁸ m/s

λ = wavelength = 695 nm = 695x10^-9 m (convert to m to be consistent with units of c)

E = (6.626x10^-34 Js)(3x10⁸ m/s) / 695x10^-9 m

E = 2.86x10^-19 J