Question

What is the amount of energy for a photon that has a 125 cm wavelength

Answer 1

Answer:

1.59 x 10⁻²⁵ J.

Explanation:

• The energy of a photon is calculated Planck - Einstein's equation:

E = h ν , where

E is the energy of the photon,

h is  Planck's constant (h = 6.626  x 10 ⁻³⁴ J.s)

ν  is the frequency of the photon

• There is a relation between the frequency (ν ) and wave length (λ).

λ.ν = c,

where c is the speed of light in vacuum (c = 3 .0 x 10 ⁸ m/s).

λ = 125 cm = 1.25 m.

Now, E = h.c/λ.

∴ E = h.c/λ = (6.626  x 10 ⁻³⁴ J.s) (3 .0 x 10 ⁸ m/s) / (1.25 m) = 1.59 x 10⁻²⁵ J.