Given:
Wavelength (λ) of red light = 725 nm
To determine:
Energy associated with the given wavelength
Step-by-step explanation:
The relation between energy (E) and wavelength (λ) is given as-
E = hc/λ
where : h = Planck's constant 6.626 * 10⁻³⁴ Js
c = speed of light = 3*10⁸ m/s
E = 6.626*10⁻³⁴ Js * 3*10⁸ ms⁻¹/725*10⁻⁹ m = 2.74*10⁻¹⁹ J
Ans: Energy associated with a wavelength of 725 nm is 2.72*10⁻¹⁹ J