A photon of light produced by a surgical laser has a wavelength of 821 nm. What is the energy of this photon? (note: h = 6.626 x
10-34 J.)

E =  0.024 ×10⁻¹⁷ J

Explanation:

Given data:

Wavelength of photon = 821 nm (821 ×10⁻⁹ m)

Energy of photon = ?

Solution:

Formula:

E = hc/λ

h = plancks constant = 6.626×10⁻³⁴ Js

c = speed of light = 3×10⁸ m/s

by putting values

E = 6.626×10⁻³⁴ Js × 3×10⁸ m/s / 821 ×10⁻⁹ m

E = 19.878×10⁻²⁶ J.m/ 821 ×10⁻⁹ m

E =  0.024 ×10⁻¹⁷ J

c) should be the answer.